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	<id>https://wiki.prebid.org/index.php?action=history&amp;feed=atom&amp;title=Ads.txt</id>
	<title>Ads.txt - Revision history</title>
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	<updated>2026-06-04T21:11:10Z</updated>
	<subtitle>Revision history for this page on the wiki</subtitle>
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	<entry>
		<id>https://wiki.prebid.org/index.php?title=Ads.txt&amp;diff=333&amp;oldid=prev</id>
		<title>Jkoran at 15:57, 13 February 2021</title>
		<link rel="alternate" type="text/html" href="https://wiki.prebid.org/index.php?title=Ads.txt&amp;diff=333&amp;oldid=prev"/>
		<updated>2021-02-13T15:57:10Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table class=&quot;diff diff-contentalign-left diff-editfont-monospace&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 15:57, 13 February 2021&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l1&quot; &gt;Line 1:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 1:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;−&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Ads.txt (&amp;quot;ADS&amp;quot; is an acronym for Authorized Digital Sellers) is method for publishers to designate the vendors they rely on to increase the demand for their inventory. Sellers place a file containing a list of sell-side partners in a well-known location hosted on their domain.&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;+&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Ads.txt (&amp;quot;ADS&amp;quot; is an acronym for Authorized Digital Sellers) is method for publishers to designate the vendors they rely on to increase the demand for their inventory.&lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;&amp;lt;ref&amp;gt;https://iabtechlab.com/ads-txt&amp;lt;/ref&amp;gt; &lt;/ins&gt;Sellers place a file containing a list of sell-side partners in a well-known location hosted on their domain.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The goal of Ads.txt was to help buyers understand if a seller was spoofing a publisher domain by seeing if that publisher had listed this seller in Ads.txt file.  &lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The goal of Ads.txt was to help buyers understand if a seller was spoofing a publisher domain by seeing if that publisher had listed this seller in Ads.txt file.  &lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l11&quot; &gt;Line 11:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 11:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The Ads.txt file can optionally include an organizational identifier issue by Tag:&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The Ads.txt file can optionally include an organizational identifier issue by Tag:&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;−&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;* TAGID (&lt;del class=&quot;diffchange diffchange-inline&quot;&gt;ex&lt;/del&gt;. f08c47fec0942fa0)  &lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;+&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;* TAGID (&lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;e&lt;/ins&gt;.&lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;g., &lt;/ins&gt;f08c47fec0942fa0)  &lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The relationship type can be either &amp;quot;direct&amp;quot; or &amp;quot;reseller.&amp;quot;  The designation of &amp;quot;direct&amp;quot; means SSP or exchange will itself sell the publisher's inventory. The designation of &amp;quot;reseller&amp;quot; means the SSP or exchange will sell the publisher inventory itself as well as request demand from other SSPs and exchanges.&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The relationship type can be either &amp;quot;direct&amp;quot; or &amp;quot;reseller.&amp;quot;  The designation of &amp;quot;direct&amp;quot; means SSP or exchange will itself sell the publisher's inventory. The designation of &amp;quot;reseller&amp;quot; means the SSP or exchange will sell the publisher inventory itself as well as request demand from other SSPs and exchanges.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot;&gt; &lt;/td&gt;&lt;td class='diff-marker'&gt;+&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot;&gt; &lt;/td&gt;&lt;td class='diff-marker'&gt;+&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Publishers may choose to designate in their Ads.txt file &amp;quot;placeholder&amp;quot; information to signal that they alone sell their own inventory.&amp;lt;ref&amp;gt;https://iabtechlab.com/wp-content/uploads/2020/12/ads-txt-v1.0.3_Draft_in_Public_Comment_IABTechLab_2020-12.pdf&amp;lt;/ref&amp;gt; This signal replaces the deprecated empty Ads.txt file some publishers had previously used.&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== History ==&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== History ==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l30&quot; &gt;Line 30:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 32:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== See Also ==&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== See Also ==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;* [[Sellers.json]]&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;* [[Sellers.json]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot;&gt; &lt;/td&gt;&lt;td class='diff-marker'&gt;+&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;* [[Schain]]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== References ==&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== References ==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Jkoran</name></author>
	</entry>
	<entry>
		<id>https://wiki.prebid.org/index.php?title=Ads.txt&amp;diff=332&amp;oldid=prev</id>
		<title>Jkoran: /* Impact */</title>
		<link rel="alternate" type="text/html" href="https://wiki.prebid.org/index.php?title=Ads.txt&amp;diff=332&amp;oldid=prev"/>
		<updated>2021-02-13T15:51:03Z</updated>

		<summary type="html">&lt;p&gt;&lt;span dir=&quot;auto&quot;&gt;&lt;span class=&quot;autocomment&quot;&gt;Impact&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;table class=&quot;diff diff-contentalign-left diff-editfont-monospace&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 15:51, 13 February 2021&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l24&quot; &gt;Line 24:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 24:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Despite its laudable goal, Ads.txt is often criticized for the friction it introduces for publishers to improve their yield. Moreover, the inability for a reseller to signal that its partners are authorized to sell the inventory to marketers defeats the original purpose of having a signal from publisher to prospective buyers as to whether a given seller is spoofing its domain. &amp;lt;ref&amp;gt;https://www.adexchanger.com/the-sell-sider/why-ads-txt-has-failed-and-what-to-do-about-it/#more-149089&amp;lt;/ref&amp;gt; This limitation is addressed by [[Sellers.json]].&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Despite its laudable goal, Ads.txt is often criticized for the friction it introduces for publishers to improve their yield. Moreover, the inability for a reseller to signal that its partners are authorized to sell the inventory to marketers defeats the original purpose of having a signal from publisher to prospective buyers as to whether a given seller is spoofing its domain. &amp;lt;ref&amp;gt;https://www.adexchanger.com/the-sell-sider/why-ads-txt-has-failed-and-what-to-do-about-it/#more-149089&amp;lt;/ref&amp;gt; This limitation is addressed by [[Sellers.json]].&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt;−&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Another limitation of this design is the centralized licensing scheme, publishers use to signal the buyers which organizations are authorized sellers and resellers. The organizational identifiers are managed by a central authority, which requires a fee to issue the identifier. An alternate decentralized approach would be to rely on the public/privacy key each  organization already relies on to validate HTTPs, which would eliminate the &lt;del class=&quot;diffchange diffchange-inline&quot;&gt;unneccesary &lt;/del&gt;overhead and cost incurred by relying on a central authority to license organizational identifiers.  &lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt;+&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Another limitation of this design is the centralized licensing scheme, publishers use to signal the buyers which organizations are authorized sellers and resellers. The organizational identifiers are managed by a central authority, which requires a fee to issue the identifier. An alternate decentralized approach would be to rely on the public/privacy key each  organization already relies on to validate HTTPs, which would eliminate the &lt;ins class=&quot;diffchange diffchange-inline&quot;&gt;unnecessary &lt;/ins&gt;overhead and cost incurred by relying on a central authority to license organizational identifiers.  &lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Given these issues the ecosystem is looking into better forms of signaling throughout the distributed advertising supply chain that supports publishers' businesses.&lt;/div&gt;&lt;/td&gt;&lt;td class='diff-marker'&gt; &lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Given these issues the ecosystem is looking into better forms of signaling throughout the distributed advertising supply chain that supports publishers' businesses.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Jkoran</name></author>
	</entry>
	<entry>
		<id>https://wiki.prebid.org/index.php?title=Ads.txt&amp;diff=330&amp;oldid=prev</id>
		<title>Jkoran: Created page with &quot;Ads.txt (&quot;ADS&quot; is an acronym for Authorized Digital Sellers) is method for publishers to designate the vendors they rely on to increase the demand for their inventory. Sellers...&quot;</title>
		<link rel="alternate" type="text/html" href="https://wiki.prebid.org/index.php?title=Ads.txt&amp;diff=330&amp;oldid=prev"/>
		<updated>2021-02-13T15:23:47Z</updated>

		<summary type="html">&lt;p&gt;Created page with &amp;quot;Ads.txt (&amp;quot;ADS&amp;quot; is an acronym for Authorized Digital Sellers) is method for publishers to designate the vendors they rely on to increase the demand for their inventory. Sellers...&amp;quot;&lt;/p&gt;
&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;Ads.txt (&amp;quot;ADS&amp;quot; is an acronym for Authorized Digital Sellers) is method for publishers to designate the vendors they rely on to increase the demand for their inventory. Sellers place a file containing a list of sell-side partners in a well-known location hosted on their domain.&lt;br /&gt;
&lt;br /&gt;
The goal of Ads.txt was to help buyers understand if a seller was spoofing a publisher domain by seeing if that publisher had listed this seller in Ads.txt file. &lt;br /&gt;
&lt;br /&gt;
The Ads.txt file contains a minimum of three pieces of information: &lt;br /&gt;
&lt;br /&gt;
* Domain name of the sell-side partner (e.g., appnexus.com)&lt;br /&gt;
* Account ID (e.g., 4052)&lt;br /&gt;
* Relationship type (e.g., reseller)&lt;br /&gt;
&lt;br /&gt;
The Ads.txt file can optionally include an organizational identifier issue by Tag:&lt;br /&gt;
&lt;br /&gt;
* TAGID (ex. f08c47fec0942fa0) &lt;br /&gt;
&lt;br /&gt;
The relationship type can be either &amp;quot;direct&amp;quot; or &amp;quot;reseller.&amp;quot;  The designation of &amp;quot;direct&amp;quot; means SSP or exchange will itself sell the publisher's inventory. The designation of &amp;quot;reseller&amp;quot; means the SSP or exchange will sell the publisher inventory itself as well as request demand from other SSPs and exchanges.&lt;br /&gt;
&lt;br /&gt;
== History ==&lt;br /&gt;
&lt;br /&gt;
Google created Ads.txt in spring 2017 and relied on the Interactive Advertising Bureau (IAB) Tech Lab to propagate its use by publishers. &lt;br /&gt;
&lt;br /&gt;
Within a year, fraudsters exploited the weaknesses in the design by copying valid Ads.txt files onto their own domains, which may use stolen content from real publishers.&amp;lt;ref&amp;gt;https://www.thedrum.com/news/2019/02/07/fraudsters-target-adstxt-industry-calls-uncluttered-supply-chain&amp;lt;/ref&amp;gt; Some fraudsters copied valid Ads.txt files but did not even both to place content on their own domains.&amp;lt;ref&amp;gt;https://digiday.com/marketing/ads-txt-404bot&amp;lt;/ref&amp;gt; &lt;br /&gt;
&lt;br /&gt;
== Impact ==&lt;br /&gt;
Despite its laudable goal, Ads.txt is often criticized for the friction it introduces for publishers to improve their yield. Moreover, the inability for a reseller to signal that its partners are authorized to sell the inventory to marketers defeats the original purpose of having a signal from publisher to prospective buyers as to whether a given seller is spoofing its domain. &amp;lt;ref&amp;gt;https://www.adexchanger.com/the-sell-sider/why-ads-txt-has-failed-and-what-to-do-about-it/#more-149089&amp;lt;/ref&amp;gt; This limitation is addressed by [[Sellers.json]].&lt;br /&gt;
&lt;br /&gt;
Another limitation of this design is the centralized licensing scheme, publishers use to signal the buyers which organizations are authorized sellers and resellers. The organizational identifiers are managed by a central authority, which requires a fee to issue the identifier. An alternate decentralized approach would be to rely on the public/privacy key each  organization already relies on to validate HTTPs, which would eliminate the unneccesary overhead and cost incurred by relying on a central authority to license organizational identifiers. &lt;br /&gt;
&lt;br /&gt;
Given these issues the ecosystem is looking into better forms of signaling throughout the distributed advertising supply chain that supports publishers' businesses.&lt;br /&gt;
&lt;br /&gt;
== See Also ==&lt;br /&gt;
* [[Sellers.json]]&lt;br /&gt;
&lt;br /&gt;
== References ==&lt;br /&gt;
&lt;br /&gt;
&amp;lt;references /&amp;gt;&lt;br /&gt;
[[Category:Glossary|Ads.txt]]&lt;/div&gt;</summary>
		<author><name>Jkoran</name></author>
	</entry>
</feed>