Zynga shares plummeted more than 10 percent after the game maker and Facebook revised their 2-year-old agreement, now treating Zynga with the same rules as it applies to all other game developers. Most importantly, these new terms prevent Zynga from driving gamers from Facebook to Zynga.com. This rule, the same as Facebook applies to other game developers, ensures that Facebook retains those gamers — and the revenue that comes along with them.

Here's why we should actually be paying very close attention: a Facebook mobile ad network, if successful and widely adopted, would dramatically increase the amount of money media and tech companies are able to make in the next decade.

Using cookies and re-targeting, Facebook now plans to give companies more specific advertising data.