Lack of Profits
Google's (Nasdaq:GOOG) revenue was $1.47 billion when it went public in August 2004. Facebook had annual revenue of $3.71 billion when it IPO'd in 2012. Both were considerably larger than Twitter in terms of revenue (2012 revenue $317 million) when offering its shares to the public. Not only that but they made money — something Twitter does not.
Twitter has 218 million monthly active users (MAU) who each generate $1.47 in annual revenue. That's an operating loss of 35 cents per user. When Facebook went public it had 901 million MAUs each generating $4.11 in annual revenue and $1.96 in operating profit.
It now has five times the users Twitter does. Of even greater importance is the fact that Facebook has grown its MAU's on an annualized basis by 11.5% over the past 27 months.
Meanwhile, Twitter's annualized growth rate in terms of MAUs was just 7% in its most recent quarter, much less than the 10%-11% it was averaging previously. I don't know what Twitter's break-even point is in terms of MAUs but it's definitely greater than 218 million.
Based on first-half results at the end of June, Facebook's annualized revenue and non-GAAP operating profit per MAU is $5.69 and $2.37, respectively. Since its IPO in May 2012 it's been able to increase monthly active users by 28% to 1.15 billion.