Twitter has always grown up in the shadow of Facebook (FB).
Facebook was started in 2004 in the dorms of Harvard. Twitter was started when Jack Dorsey sent an SMS message at 9:50pm PT on March 21, 2006.
Facebook got more early venture capital money. It saw bigger growth. It attracted more “mainstream tech” managerial talent like Owen Van Natta, Gideon Yu fresh off of selling YouTube to Google (GOOG), and Sheryl Sandberg to come in as COO. Facebook’s revenues have been bigger and faster in coming compared to Twitter. And, of course, Facebook IPO’ed last May, while conventional wisdom is that possibility is still a couple of years away for Twitter.