According to The Economics of Podcasting, a new report issued by Nielsen Analytics, about 6 percent of U.S. adults have downloaded at least one podcast in the past 30 days. Yet that small percentage appears to be enough for Sony Pictures, Shell Oil, Earthlink, HP and HBO to consider this new medium a viable advertising outlet.

The Nielsen report also notes that the most popular podcasts are drawing 2 million downloads a month, around 1-2 podcasts a week, from 9 million web useres. Most podcast downloaders are male (75%). Thirty-eight percent of those downloaders note that as a result of the downloads they are listening less to radio.

One popular podcast, the Mommycast Podcast Series, with content directed specifically at women, inked an advertising deal this year with the Dixie Paper Company worth more than $100,000. Advertisements on Mommycast are embedded in the podcast, a strategy that advertisers may need in order to keep listeners from fast-forwarding over their messages. The survey notes that 60% of listeners fast-forward over commericals.