Facebook's $400M-$500M Acquisition Of Video Ad Tech Startup LiveRail Is Now Official

 Facebook’s acquisition of LiveRail closed today, a source told me, and Facebook confirms to me the deal is now official. Facebook announced the buy without disclosing a price back on July 6th, but multiple sources told TechCrunch the price was between $400 million and $500 million. Regulators apparently had no issue with Facebook buying LiveRail, which help brands that want to buy…