The Bear Stearns analyst also said Yahoo! could be a potential buyer if it does not want to miss out on the networking phenomenon.
In a client note, Mr Peck said he saw Facebook generating $140 million (€101.5m) in revenue this year and $358m (€259.6m) of earnings in 2008, growing to $6bn (€4.3m) of revenues with $2.3bn (€1.7bn) in earnings before interest, tax, depreciation and amortisation by 2016.
He concludes that Facebook is worth “as much as $5bn-$6bn”.
“Our opinion is that Yahoo! needs to step up its initiatives in this area relatively shortly, or risk being marginalised in some of their businesses,” the note by Mr Peck reads.
“Further, while valuations could look daunting at first blush, we believe the rapid growth of these sites provide strong monetisation opportunities.”
Mr Peck is an analyst with global investment bank Bear Stearns.
Last year, Mark Zuckerberg, Facebook.com’s mastermind turned down a $1bn approach from Yahoo!
Peter Thiel, a Facebook director and early backer, recently suggested the company could fetch as much as $10bn in a sale.
Social networking has undergone a boom in popularity in the last year and according to comScore statistics, Facebook’s audience grew by more than 270% to 52.2m users in the 12 months to June this year — far outpacing the increase at Bebo, which saw a rise of 172% to 18.2m users and MySpace, which grew by 72% to 114.1m.
The sites have well over one million users in Ireland.
A report from Visa and Yahoo! revealed that people who use online media are more likely to buy online than other web users.