AOL has bought out Sphere, a blog and news contextual display service, for an undisclosed amount. The startup operates in a crowded contextual content display space with competition from the likes of Inform, AggregateKnowledge and many others. Sphere will be part of the company’s programming division, under Bill Wilson. Since its start, it has refreshed its business model a few times, from being a blog search engine (a business black hole till now) to a contextual content service provider for bigger sites such as WSJ.com, Time.com and others. AOL had previously been working with Sphere to offer its widget technology on AOL News.