Why he matters: Chances are you've passed through one of Diller's portals without even knowing it. His IAC/InterActiveCorp owns dating site Match.com, event organizer Evite, mortgage company LendingTree, and search engine Ask.
But Diller isn't putting all his chips on the Web: Most of IAC's revenue is generated by HSN (formerly the Home Shopping Network) and Ticketmaster. What's next? Diller has hired longtime television producer Michael Jackson to develop niche sites like CollegeHumor.com, while a joint venture with the Huffington Post (see No.38) will produce Daily Show-style satirical news for the Web.