One trivia site I go to has that annoying popup asking you to download free screen savers. Those things have been around for 10 years- why the hell do they do it? Aart from to annoy me?
Is there money to be made out of pop ups that drive people nuts?
Well, my dad was gullible enough to download a few screensavers from them. At that time, they just had advertisements built in, But, nowadays, they often have spyware. Advertisers pay a lot of money to find out what the more gullible people do online, as they are the most likely to buy their products.
Remember, in a large population, even a .01% return rate can be profitable.