Bridge Ratings, a radio research company, projects that by 2010 podcast audience growth is expected to reach a conservative 45 million users who will have ever listened to a podcast. Aggressive estimates place this number closer to 75 million by this date.

The study estimates that 4.8 million persons have at some time during 2005 downloaded a podcast from either a radio station or other source. iTunes was referrenced as the most often accessed portal for podcast downloads. This 4.8 million estimate is up from 820,000 podcast users in 2004.