ShareThis makes a very useful service that might be sheltering a real business.
Let's deal with this product first, since it's quite good. ShareThis makes a widget that any content publisher can use on his or her sites. It gives users a very easy way to share a story they are reading with a site like Digg or Reddit, or with individuals via their social network, or through e-mail or instant message. And it beats littering a blog template with a dozen buttons that appear on every story.
ShareThis takes this feature to gratifying extremes. If you want to share a story via Facebook, ShareThis can read in your Facebook contact list, so that addressing a message is a simple matter of selecting a user from a drop-down friends list. Users can also save ShareThis profiles, so that no matter where on the Net they go, if the site uses ShareThis, their preferences and their address books copy over. (There's also a ShareThis bookmarklet, which can be used on any site anywhere).
It's handy, but so far, maybe not so exciting. Where ShareThis becomes more than just a fancy widget, and edges into possible business viability, lies in its collection and treatment of data about its users' activities. ShareThis knows which stories users engage with--the ones they forward and save. Compared with Google, ShareThis gets more interesting data from Web surfers. Although somewhat less of it.
CEO Tim Schigel is giving ShareThis away to publishers, along with valuable tracking and usage data. He hopes to monetize this function via very targeted advertising. "We're not doing it yet," Schigel told me, but he's an experienced online ad man, and convinced that the deep data he'll get from ShareThis widgets will equal big bucks.
Given mass adoption of his service, he'll be proven right. ShareThis will be able to deliver ad messages at the point of action--when a user is about to share a file--and with full awareness of the content they are most interested in. Of course, there's mass adoption and there's mass adoption. ShareThis may lock up some big accounts (major publishing brands) which will earn it a nice income, but the really big play requires ubiquitous presence everywhere, from the New York Times to the "long tail" of all online content.
I've embedded the ShareThis widget for this story here: