When Zynga (ZNGA) first went public, the excitement around the company's innovative business model and huge number of active users led to what many felt to be a very overvalued public offering, and share prices subsequently crashed hard afterwards. Now that the company is so cheap, though, is this the real time to buy Zynga and profit from a rebound, or is its business model just too unproven and unreliable? In this video, Motley Fool tech analyst Andrew Tonner gives you several of the metrics you need to be watching to see which way this company is really headed.