Twitter’s core strength—limiting posts to 140 characters—has created opportunities for other websites and apps to siphon off and capture users around activity that originated on Twitter. These new sites and services leverage Twitter’s distribution pipes, free of charge, offering little or nothing in return. In 2010, these common tweeting behaviors created opportunities for new entrepreneurs to leverage. In pictures, Instagram became a hit with its range of filters and sharing features while users could also choose to have their in-app photos hosted by external blogging sites such as Posterous . For introductions, Hashable provided a service whereby users could easily exchange contact information and keep track of what introductions they were a part of. The act of posing questions in tweets has been captured by Quora . Twitter users’ fascination with entertainment and sports has prompted Twitter hiring its own employee ( @omid ) in the Los Angeles area (and dedicating separate servers for Justin Bieber ). On the political side, Twitter has made key hires from the DC beltway, and its possible a startup like Votizen could leverage the platform to help organize political interests online. Sports fans have sites like Fanvibe . For current events and information, Twitter helps drive traffic to a host of tech blogs , news blogs, and financial blogs, which themselves can be real lifestyle businesses. I’m sure there’s a business opportunity somewhere to collect and interact with Twitter users based on their expression of mood and emotion, though there could be some health and privacy concerns there. But, what about location? Is there a real, sustainable, long-term business model in location for Twitter?