Before Twitter added its own URL shortener, t.co, to the network, pretty much everybody who wanted to use shortened links to save that precious 140 character space used Bitly.
Indeed, many still use Bitly (we do at Mediabistro), because it offers analytics and other functionality that, for a long time, was both unique and incredibly powerful. Twitter’s caught up significantly since, but Bitly still has considerable value.
And it’s huge: about 286 million Bitly links are clicked each day, driving traffic to websites all around the world. Check the visual below for more data, which comes directly from Bitly themselves.