Publishers who’ve adopted ads.txt to their websites have experienced errors that could be costing them money, according to a number of reports.

Ads.txt was launched in November by the IAB UK to combat ad fraud and improve transparency during the transactions process between publishers and sellers. The tool involves a simple text file which publishers host on their websites to list all the suppliers who are authorised to sell inventory on their behalf.

However, according to ad tech company, thousands of publishers who’ve integrated ads.txt have had errors in their files, such as typos or syntax errors, leading to sellers not being recognised.

A separate analysis of 30,000 websites found around 15% of publishers that have adopted ads.txt have made errors which could also lead to potential loss of revenue.

Growing slowly

Additional analysis on the implementation ads.txt has shown slow growth since its launched last month.

Ad tech giant Google reported that 750 of the top 2,000 publisher websites have ad.txt installed (38%) while another study by MediaRadar found only 20% of the top 3,000 publisher websites have implemented the tool.

By country, 36% of publisher websites in the US are using ads.txt followed by Canada (29%), Australia (28%), Norway (28%) and France (28%).

Todd Krizelman, chief executive officer at MediaRadar described the uptake from publishers on ads.txt as “modest”.

“Only 20% of all publisher sites we track today have taken advantage of ads.text. It’s a reminder of the power of inertia, and the importance to really evangelize the benefits of this new way to stop spend on unauthorized counterfeit ad inventory,” he added.

Counterfeit inventory

Another study involving 16 publishers and tech companies including Amobee, Google and Quantcast found publishers are losing up to £2.6 million a day on counterfeit inventory as a result of not implementing ads.txt

The risks for publishers not adopting ads.txt can be a blow to their revenue stream and also running risk of counterfeit inventory where advertiser money spent on buying premium publisher inventory pulls to a fake website instead.