What does matter is that a lot of people spend a lot of time on Facebook. And it is growing.
You keep asserting this with no proof of it other than the PR figures from facebook..and anecdotal "I see lots of young people around me using it"..inspite of the fact that others don't ..and that all they see is mainly 24/7 use by unemployed people with nothing else to do ..or children ..
Reminds me of CB radio on the late 70s and early 80s in the UK ..same user demographic ..most of them talking via electronics to someone two houses away from them in real life..and feeling geekily social about it ..
I made a great deal of money in those times from selling AM and sideband radios and later FM CB sets to people in the UK who wanted to pretend to be USA truck drivers ..or Chuck Norris or whatever was going on in their heads..and who thought with a 40 channel CB and saying ten four..that they were radio hams..
Many on facebook talk about "my website on facebook"..most are exactly what Mark thinks they are ..and they don't convert..
You cant make up for lousy ROI or even losses, by increasing quantity..especially when the user figures are fantasy..