WSJ: Inside Wal-Mart's Black Friday Facebook Play

The Wall Street Journal this weekend went inside Wal-Mart Stores Inc.'s Black Friday experiment with Facebook, which the newspaper says is key to the social media giant's advertising future:

Over the next 72 hours Facebook and Wal-Mart rolled out the social network's biggest mobile-advertising campaign ever, consisting of 50 million ads. Wal-Mart's discounted deals on toys and televisions popped up in the Facebook mobile news feeds of tens of millions of people.

Unlike previous campaigns, for which companies paid Facebook only after users saw their ads, Wal-Mart prepurchased the ads and edged out other retailers for space during the all-important kickoff to the holiday shopping season.

Facebook now is considering making the option available to other companies.

In all, Wal-Mart bought more than 2 billion ads on Facebook -- three times more than last year -- as part of its evolving mobile and social media strategy, which we've examined here and noted here. For Wal-Mart, this year's results appear to be mixed, but there's still lots of learning to do.

The stakes are high for Wal-Mart as it tried to grow its online business. And this has been a crucial test for Facebook as its continues to refine is advertising platform, striking a delicate balance between its status as an online hang-out and its priorities as an ad-driven business.