Facebook did not disclose a price for the San Francisco-based company, which was founded in 2007 and has offices in several countries.
LiveRail’s technology automatically pairs video ads with the videos that appear on many websites, such as the sites for Major League Baseball, ABC and A&E Networks.
Facebook would not discuss plans for using the technology on its own website.
In March, Facebook began offering 15-second video ads from a limited number of companies on its website. The company has moved cautiously in introducing the video ads on its social network to prevent a backlash from users who might find the ads annoying.
Video ads command higher prices than other forms of online advertising such as banner ads. Facebook and internet rivals like Google are increasingly trying to grab a slice of lucrative TV-marketing budgets as they try to sustain rapid growth.