In an interview at an event thrown by tech site Re/code, YouTube CEO Susan Wojcicki dropped some info on just how big the site has become:

One nugget that Wojcicki shared was that 50 percent of YouTube views are now coming from mobile devices. She also said that the site is growing 50 percent each year in terms of watch time (although she conceded that YouTube watch time still doesn’t come close to the average amount of time consumers watch TV each day).

All told, it’s estimated YouTube generates something like $5 billion a year in ad revenue. Given the company’s growth, that number is sure to go up.