[_njyk]

It's not more annoying than a skippable YouTube pre-roll ad (which is sometimes directly encoded into the video feed by the streamer).

From an advertiser perspective, of course it works if you have a product to sell to the audience visiting the website (a mobile game, etc...).

A popunder is really no different from YouTube ads, except the advertisement doesn't cover the page content nor blocks it.

Some of the networks are even so confident that they will bring you new revenues and make you profitable that they will take the financial risk on their side (you just give the product and agree on a revenue-share and they pay all the traffic acquisition from their pocket).

Not even AdWords offers that (you take all the risk, and when you are down 100K USD, Google just says "hey, too bad, but thank you for the money, if you want you can put 500K again to make a test")