All the while, ads for dozens of high-profile brands are still regularly appearing on infringing sites -- including from companies with skin in the game like AT&T and Disney, though they're not complicit in the practice -- according to Annen-berg Innovation Lab at USC's second monthly Ad Transparency Report, released Wednesday.
The first report, which drew on a year's worth of data spanning 2012, showed Google and Yahoo among top offenders for pirate-site ad placement last year. But Google, which had already been actively dismantling its advertising connections to content theft, dropped off the list in January.
That opened the way for British firm Propellerads.com to step up its service of the pirate market, landing at No. 1 in the latest survey. Yahoo's ad exchange Right Media continues to be a major ad provider on pirate sites, as does Quantcast, which also places ad properties owned by companies like NBCUniversal and Viacom.
The list keeps shifting as "there are always new entrants to this incredibly dynamic ad network market," the report states, noting that four companies -- Admxr, Adtransfer, Mgid and Adcash -- are new to this month's top 10. Rounding out that group are Sumotorrent, Exoclick and Infolinks.
More than 150,000 pirate entertainment destinations have emerged since the 2001 birth of large P2P Internet sites, particularly in the past five years of broadband explosion, and advertising generates a vast majority of their revenue. Unlike its first report, Annenberg included a sampling of brands it found advertising on offending sites, including Amazon, AT&T, Verizon and a Disney-branded Visa card. The sampling -- made up of mostly non-media companies, with several carmakers like BMW and General Motors among those found -- does not reflect which ads or brands appear most frequently, nor was it comprehensive. Other brands included shoe companies Converse and K-Swiss, insurance companies Nationwide and Progressive and several more car companies including Buick, Honda, Lexus, Mazda and Mercedes Benz.
Because those companies' ads are being serviced through massive aggregators, they often have no control over -- and in many cases, no knowledge of -- their appearance on pirate sites.
Prof. Jonathan Taplin, director of the Innovation Lab, launched the monthly survey last month to inform brands' decisions about online ad spends. The latest installment observed ad activity on pirate sites from Jan. 1 to Jan 31.
Update: An earlier version of this story said Adultfriendfinder.com has emerged as a major advertiser on pirate sites. After this story was published, the Annenberg Lab said it was no longer supporting that assertion.