Reports today that Apple is considering putting advertisements in iTunes. This is not as new as it seems as ads already appear embedded within Podcasts. But the ability to truely target viewers and know precisely who is watching what is a tempting prize for advertisers.
Of course, the real opportunity here would be for Apple to provide consumers with more options. I have earlier written that to provide books with and without ads, at different prices, might make sense for publishers. The same is true of podcasters and even those 'publishing' music. Provide users with the option to download a podcast for free with ads or pay for one without them. That allows you to match consumer preferences or dis-satisfaction over ads with additional sources of revenue to cover the largely fixed costs associated with providing content.