After its initial public offering proved to be overvalued, shares of Facebook (META -0.29%) fell dramatically, but at these prices they look a lot more reasonable. In this video, Motley Fool tech analyst Andrew Tonner gives investors a few things to consider when thinking about buying into Facebook. He talks about its recent advertising refocus away from display ads and toward sponsored ads within a person's Facebook feed, which is finally helping the company capitalize on the burgeoning mobile industry, and highlights the world's many emerging markets where Internet penetration still has a huge distance to run, which could mean millions of new Facebook users.