Rick Bruner: Pop-Unders: Cockroaches
That's one way of putting it. I think the pop-under is the equivalent of a street peddler. They have no concern as to what you are in the middle of. They usually peddle some gimmicky product that has no legitimate value. They're persistent little buggers, who can't take a hint.

The web is my place -- "our" place. The argument that we'll "get used to" this scum of advertising is ridiculous -- and this is how most marketers legitimize this trade. We succumbed to TV advertising, 468X60's, Radio Spots, Billboards -- we'll succumb to pop-unders. This couldn't be further from the truth. Customers "own" a portion of the web. Pop-unders trespass on our property. There is absolutely no value to customers -- and businesses -- for that matter in pop-unders. Someone had the idea of posting a pop-unders not served here on sites that don't use them. I think that's a terrific idea. The pop-under is destroying online advertising's credibility and is minimizing it's potential to something simplistic and hated.

Kudos to Organic for refusing to buy them for their clients. Nice work.