If Facebook wanted to turn on mobile advertising it would instantly become the largest "mobile ad network" on the planet. Indeed, I believe after the IPO Facebook will be all but compelled to run ads on its mobile apps and HTML site. But how much money might Facebook stand to gain from such a move?
A great deal is the short answer. Let's do some simple math to find out.
Facebook now has more than 1 trillion monthly page views on a global basis. In the US the number of monthly page views is 300 billion. According to an analysis by Hubspot in May, 2011 roughly 33% of Facebook's traffic was coming from mobile devices.
If that formula is correct, then approximately 99 billion of Facebook's monthly US page views come from mobile devices. This is mind boggling.
If we use a $2.50 mobile CPM ($2.50 per 1K impressions) to value this inventory it would mean that Facebook would be in a position to instantly add $247.5 million in US ad revenue to its coffers -- assuming 100% fill.
On a global basis, using the same crude formula, Facebook's inventory would be worth approximatley $2.5 billion, the annual mobile ads run rate that Google announced last week.