The radio spectrum, in its physical makeup, can only accommodate a certain number of radio stations for communities even with the federal allocation and monitoring of wattage and signal strength. Thus, the common knowledge has been that AM and FM are non-renewable resources.
But, with the advent of Internet Radio, Wi-Fi, Satellite Radio, Cell Phone Radio, MP3s, Podcasting, and other technologies, even if Radio is still physically limited on AM and FM, it is anything but physically limited.
We have to stop thinking of Radio in terms of the method of delivery and start thinking of it as a commodity, delivered by various methods.
When a 15-year-old teenager in Des Moines, Iowa, can start an Internet Radio stream on his allowance money that can be heard not only across the U.S.A. but also around the world, its time to let the paradigm shift a little.
Radio has become a renewable resource because now we can create stations via satellite, across cell phone networks, and on the Internet. Satellite and cell phone stations and streams already have as powerful a reach as AM and FM and as more cities become completely Wi-Fi capable, Internet radios un-tethering from the computer will give it the same reach.
Privatization would allow AM and FM stations to become more competitive
By selling off all the available frequency allocations, more radio stations will be put into the hands of smaller companies and entrepreneurs.
By nature, more competition will ensue. For instance, at the moment Clear Channel owns 1200 or so stations. If given the chance to privatize, it might only consider buying 600 or 800. The remaining frequencies would be divided up, leaving hundreds of properties in other hands.
Because AM and FM are already awash in a sea of competition from newer technologies, it would behoove new owners to be more competitive not only against other AM and FM properties in their local market but against these new radio options.

