Daily deals website Groupon Inc. saw its revenue surge to $760 million last year from $33 million the previous year, with more than a third of its 2010 sales coming from outside the U.S., according to an internal memo.

The email, sent by Groupon Chief Executive Andrew Mason to staffers in early January, also reveals the founder's grand ambitions for the company he started three years ago. Mr. Mason writes that he hopes to achieve "billions in revenue" in 2011.

"By...