Radio is excepted from the national Do Not Call registry since we’re not really selling anything.
But that may not be the way your listeners see it.
When you call “inviting them to listen,” how many of them will consider that a pitch? And how pissed off will that make them?
Here’s an article which typifies what I’m talking about.
At the very least, make sure your calling list is trimmed of “Do Not Call” people. For most of these folks, if they could stop ALL calls from ALL strangers, they would.
Don’t push them into vigilante vengeance against your station.