Now that Yahoo! (NASDAQ: YHOO) has acquired Tumblr, Facebook (META -1.88%) investors may have something else to worry about. Given Yahoo!'s massive scale, the company has the potential to turn Tumblr into a force to be reckoned with. However, this may not be the primary reasoning behind why Yahoo! purchased Tumblr in the first place. In this video, Fool contributor Steve Heller examines Yahoo!'s recent acquisition and what it could mean for Facebook's future.