"Download accelerators" like installerex.com or "anonymous vpn" (they advertise getprivate.net at the moment) which installs adware. Also, Samsung advertises on TPB ( https://torrentfreak.com/samsung-exposed-as-top-advertiser-o... ). Adware can generate high revenue even on websites like TPB since the adware wont appear on TPB but replace a legitimate sites ad banner. The industry has gotten a little harder mind you, since adsense recently stopped adware software from using adsense's "custom search" ad.