You might be wondering why there are so many different kinds of adware and malware out there. Particularly because you don’t see why you’d wake up and decide that you should spend a bunch of time developing something to annoy a ton of people that you’ll never meet. It seems a bit crazy that there are people deriving enjoyment from the idea that random people all over the world have to deal with the software that you’ve written.
But adware writers aren’t concerned with that. They don’t care that you have to take time from your day to deal with pop-up advertisements and all of that. They’re far too busy spending the money that those ads gives them. Those ads that you see on your computer aren’t written by the guy who wrote the adware. That ad space isn’t sold to the adware writer either. They’re members of an advertising network that pays them for the number of people who view their ads.
Many (particularly the less scrupulous advertising networks) don’t really care who is looking at the ads. They sell, for example, ten thousand advertisement views to an advertiser. As long as they’ve shown those ten thousand views to SOMEone, they’re happy. Sheep on the other end? No problem.
This is, of course, where adware comes in. They display the ads to somewhere, rack in the advertising views, and get paid in the process. Of course, I’m simplifying a lot here, but you get the general idea: those advertisements, even if you’re just closing them, are making somebody rich at the expense of your free time and sanity.