Felix Salmon thinks companies that figure out how to monetize sharing services like Tumblr and Pinterest are the future's winners:
[T]here are 9 curators for every creator on [Tumblr]. Reblogging, on Tumblr, is so easy that the vast majority of Tumblr sites actually create little or no original content: they just republish content from other people. That’s a wonderful thing, for two reasons. Firstly, it takes people who are shy about (or just not very good at) creating their own content, and gives them a great way to express themselves online. (As Arianna Huffington says, “self-expression is the new entertainment”.) And secondly, it acts as a natural amplifier for the people who do create original content — the average post on Tumblr gets reblogged nine times, and therefore reaches vastly more people than if it just sat on its original site waiting to be discovered by people visiting it directly…the social, digital world is one where the biggest media companies have a much lighter touch, and where the content creators with the broadest reach will be the ones who care the least about protecting their copyrights. I suspect that we’re only in the very early days of seeing how this is going to disrupt just about every media organization built on the idea of hosting a website and selling ads
The Dish 