The lure of podcasting. Forrester Research estimates that 300,000 podcasts will be available by year end, with the number of available podcasts growing to 13 million by 2009. The statistics on the number of people who listen to podcasts are a little harder to come by. Forrester estimates that this is partly to do with content and partly to do with technology. However, with Apple adding software to support podcasting with its next version of iTunes, this may change.