Facebook on Wednesday announced a deal to buy online video advertising technology company LiveRail. The companies did not disclose how much Facebook is paying for seven-year-old LiveRail. What LiveRail ultimately offers is a complete advertising solution for video publishers, Facebook vice president of ads product marketing Brian Boland said in a blog post. We believe that LiveRail, Facebook and the premium publishers it serves have an opportunity to make video ads better and more relevant for the hundreds of millions of people who watch digital video every month.