Facebook has struck a deal to acquire San Francisco-based video ad tech company LiveRail for an undisclosed amount. The acquisition could help Facebook to expand video advertising on its own platform by offering publisher better tools to buy and target ads, but it will also give the company an entry into the video ad business across the web: LiveRail's customers include publishers like ABC, MLB.com and CBS Interactive.

Facebook's Vice President of Ads Product Marketing Brian Boland announced the acquisition with a blog post, which read in part:

"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. More relevant ads will be more interesting and engaging to people watching online video, and more effective for marketers too. Publishers will benefit as well because more relevant ads will help them make the most out of every opportunity they have to show an ad."

Developing story, more to come.