What’s the reason behind AOL’s acquisition of TechCrunch for a reported $30 million, especially given AOL’s “build-first” culture? AOL CEO Tim Armstrong explained the deal to AdAge, calling it a “two-for-one transaction,” since the TechCrunch audience is loyal, in addition to the blog also having a strong advertising base. AOL has had some problems with their internal startups, and their best media properties—Engadget and Joystiq—were acquired from the outside. One of the biggest potential pitfalls—TechCrunch Editor Michael Arrington’s loud and impassioned voice that could trouble AOL’s readers—is not a concern for Armstrong, who said he would like Arrington to stick around “forever,” and the deal locked the beloved-by-readers editor into a three-year contract. Armstrong must really be in a buying mood: AOL also reportedly bought the video startup 5Min for close to $65 million.