Why does that stupid talking twins video keep popping up on random pages?

I'll be looking at a meme base site or something, listening to music on my headphones, when all of a sudden I hear this earsplitting shriek. Is the house on fire? No. One of the ads at the bottom of the page has mysteriously turned into a video with two babies screaming at each other... at full volume. That wouldn't piss me off quite as much if there any reason for it, but the video doesn't advertise anything. It doesn't link to any other site. It's just random, obnoxious noise. Why is it there?!