AD EXPANSION: Twitter is expanding the number of ads shown in its messaging mix as it gets more serious about making money.
WHAT IT MEANS: Twitter users will start seeing ads from companies that they haven't chosen to follow. That's a change from how Twitter has done things since it began allowing "promoted tweets" last year.
NO IPO TIMETABLE: Twitter isn't in a rush to join the ranks of Internet companies that have recently filed for initial public offerings of stock. Twitter just raised $400 million for venture capitalists and other investors so it could bide its time.