Soon after he got his first computer in 1999, Val Katayev, then just 17 years old, created PSX Extreme, a digital magazine all about PlayStation games. It was a fun project – but also an unintentional crash course in the potential of targeted digital marketing. 

The revenue he got from running ads on his site was nice. But companies would pay him a much larger bonus every time a click on an ad generated a sale for them. Digital ads were fairly cheap, Katayev realized, especially after the Dotcom Bubble burst in March 2000. If he placed ads on the right sites and search results pages, Katayev figured – the ones people actually looking to buy something frequented – then he could make way more money on those sales bounties than he'd spend on the campaigns.