The Outsider is correct that they can run underwriting announcements, which sound a lot like commercials but don't contain any "action item." The FCC, however, has cracked down on underwriting announcements to some degree. An LPFM outside of Austin was fined around $20,000 a few years ago for airing underwriting announcements that were too long and sounded too much like commercials. Apparently, they frown on underwriting announcements that last longer than 30 seconds.