To be fair, those figures have been disputed and also called outright fraudulent by a number of parties.
An advertiser recently had an $800,000 invoice struck off because he threatened to sue Facebook. They decided just to let it slide instead of have the public debate.
As with Skype, I wait for the day when another Facebook competitor becomes ubiquitous enough to warrant switching. I am waiting for pretty much anything, so long as it has the market share with friends and family.