As a new industry standard in the digital ad ecosystem, it's crucial that all publishers create and integrate an ads.txt file to prevent any loss of revenue, strengthen the integrity of their brand, and promote transparency in programmatic advertising.
For more information on ads.txt, see this article from Google.
Why it's important
From mid-October 2017, Google and all other buyers started not buying inventory on sites that don't have or include all the correct providers on their ads.txt.
Just as important, it's also a concentrated effort to protect a publisher's brand by reducing counterfeit inventory. Counterfeit inventory is where inventory is sourced from a domain and mislabeled on purpose to for example, sell invalid traffic or bypass content or domain blacklists.
A complete and accurate ads.txt also ensures that advertisers are buying a publisher's actual inventory and not fraudulent spaces from a spoofed domain. Domain spoofing is when third-parties imitate a site and trick demand providers into buying inventory using the publisher's brand. For example, in this Digiday article, the Financial Times estimated that $1.3 million of spoofed FT.com ad space is sold each month.
How it works
Ads.txt is a basic text file that lists all the demand providers a publisher (seller) has authorized to buy or resell their inventory.
The file is served in the publisher's root level of their domain. It must be posted there by the publisher's webmaster and is essentially a publicly accessible record.
The file specifically contains the following information for each demand provider (seller) the publisher uses in their ad configuration:
<SSP/Exchange domain>, <Your publisher ID for that provider>, <The seller's relationship with the publisher (DIRECT or RESELLER>, <The tag ID which is optional>
Marfeel's ads.txt is the following. The reason there are so many providers is a result of Marfeel's sophisticated ad setup that leverages competition among providers to maximize the value and return of a publisher's inventory:
The list can also be downloaded in .txt format here:
EMXDigital (Client + S2S)
EMXDGT.com, 137, RESELLER, 1e1d41537f7cad7f
Appnexus.com, 1356, RESELLER, f5ab79cb980f11d1
indexexchange.com, 184550, RESELLER
indexexchange.com, 186442, RESELLER
indexexchange.com, 187012, RESELLER
google.com, pub-3733785150938669, RESELLER, f08c47fec0942fa0
google.com, pub-2117324400584663, RESELLER, f08c47fec0942fa0
contextweb.com, 560011, RESELLER, 89ff185a4c4e857c
contextweb.com, 560444, RESELLER, 89ff185a4c4e857c
contextweb.com, 560782, RESELLER, 89ff185a4c4e857c
contextweb.com, 560783, RESELLER, 89ff185a4c4e857c
contextweb.com, 560938, RESELLER, 89ff185a4c4e857c
contextweb.com, 560939, RESELLER, 89ff185a4c4e857c
sovrn.com, 243540, RESELLER , fafdf38b16bf6b2b
lijit.com, 243540, RESELLER, fafdf38b16bf6b2b
gumgum.com, 11645, RESELLER, ffdef49475d318a9
openx.com, 537120960, RESELLER
openx.com, 83499, RESELLER
openx.com, 538959099, RESELLER
pubmatic.com, 137711, RESELLER
pubmatic.com, 156700, RESELLER
pubmatic.com, 156212, RESELLER
pubmatic.com, 62483, RESELLER
contextweb.com, 558511, RESELLER
sovrn.com, 247572, RESELLER, fafdf38b16bf6b2b
lijit.com, 247572, RESELLER, fafdf38b16bf6b2b
appnexus.com, 1360, RESELLER, f5ab79cb980f11d1
openx.com, 539924617, RESELLER, 6a698e2ec38604c6
rubiconproject.com, 17960, RESELLER, 0bfd66d529a55807
districtm.io, 101760, RESELLER, 3fd707be9c4527c3
loopme.com, s-2411, RESELLER, 6c8d5f95897a5a3b
loopme.com, 5679, RESELLER, 6c8d5f95897a5a3b
xad.com, 958, RESELLER, 81cbf0a75a5e0e9a
rhythmone.com, 2564526802, RESELLER, a670c89d4a324e47
smaato.com, 1100044045, RESELLER, 07bcf65f187117b4
pubnative.net, 1006576, RESELLER, d641df8625486a7b
adyoulike.com, b4bf4fdd9b0b915f746f6747ff432bde, RESELLER
rubiconproject.com, 17990, DIRECT, 0bfd66d529a55807
pubmatic.com, 155979, Reseller, 5d62403b186f2ace
pubmatic.com, 156785, Reseller,5d62403b186f2ace
pubmatic.com, 157138, Reseller, 5d62403b186f2ace
openx.com, 539639517, DIRECT, 6a698e2ec38604c6
openx.com, 539708242, DIRECT, 6a698e2ec38604c6
openx.com, 540611310, DIRECT, 6a698e2ec38604c6
appnexus.com, 9140, RESELLER, f5ab79cb980f11d1
cosmoshq.com, 1002, DIRECT
aps.amazon.com, 713b5f85-602b-49d9-a3b8-33750c16a4fc, DIRECTopenx.com, 540191398, RESELLER, 6a698e2ec38604c6pubmatic.com, 157150, RESELLER, 5d62403b186f2acedistrictm.io, 100962, RESELLERappnexus.com, 1908, RESELLER, f5ab79cb980f11d1rubiconproject.com, 18020, RESELLER, 0bfd66d529a55807rhythmone.com, 1654642120, RESELLER, a670c89d4a324e47adtech.com, 12068, RESELLER, e1a5b5b6e3255540
spotxchange.com, 170031, RESELLER, 7842df1d2fe2db34spotx.tv, 170031, RESELLER, 7842df1d2fe2db34
sonobi.com, 1d7065c722, DIRECT, d1a215d9eb5aee9erhythmone.com, 1059622079, RESELLER, a670c89d4a324e47contextweb.com, 560606, RESELLER, 89ff185a4c4e857c
districtm.io, 101887, DIRECT, 3fd707be9c4527c3appnexus.com, 1908, RESELLER, f5ab79cb980f11d1google.com, pub-9685734445476814, RESELLER, f08c47fec0942fa0
|Improve Digital (EBDA)|
improvedigital.com, 1364, DIRECT
teads.tv, 9887, DIRECT, 15a9c44f6d26cbe1
You can also download the list of Marfeel's authorized providers directly here:
The demand providers then use crawlers to find and integrate ads.txt files in their platforms to confirm that they are buying and reselling the inventory they are authorized to buy or resell. This allows bidders to ensure that the publisher and demand provider have an authentic connection and that they are not buying inventory from a fake domain or buying counterfeit inventory.
- If you already have an ads.txt file, copy and paste the above list of Marfeel authorized providers from and including #marfeel 010818 to your file and re-upload it.
- If you don't have an ads.txt:
- Download the above .txt file.
Add all the other providers you use for desktop and mobile starting at #your ad configuration, following the same format.
Upload the file to the root level of your domain (ie.) similar to your robots.txt file that instructs robots on how to crawl your site.