More than 60m Americans listen to radio over the internet each week

"More than 60 million people each week listen to radio over the Internet.
84% (50 million) of this group regularly listens for at least five minutes to AM/FM simulcast streams in a typical week.
62% (38 million) of the total streaming group regularly listens for at least five minutes listening to Internet-only streams."
Source: Device Usage Upadate from Bridge Ratings, 1st April 2010