The agreement also gives Sina the right to show out-of-game on-demand clips, highlight videos and other footage.

It's not hard to see why the NFL would go this route. Many NFL games don't start at a convenient time for Chinese viewers, so TV coverage (and of course, the high-profile ad campaigns that follow) isn't nearly as important as it is in the US. And of course, American football isn't nearly as much of a cultural institution in China as it is in its home country. Sina Weibo's livestreams could serve as a form of marketing for the NFL, giving it exposure that it otherwise wouldn't get.