I listened to Pulse 87.7, a commercial dance station in New York City. On July 20, 2009, the station did an emergency donation drive in order to be able to stay on the air. They had a big lease payment of about $150,000 due within a week. It's almost unheard of for a commercial station to solicit listener donations. But since they had a unique format that people were passionate about, the listeners opened their wallets. I personally donated $87.70 (that's in addition to the ~$400 in stocks of the company that ran Pulse 87 that ultimately became worthless), and I heard people had donated several thousand dollars to try to keep the station afloat.
But the signal owner told Pulse 87 that they are not allowed to raise money on the air. They extended the payment deadline by a few months. Pulse 87 had to give the donations back to the listeners. They ultimately went bankrupt on the day before Halloween.
I believe they had raised or would have raised whatever they needed to pay the lease, since they got over 8000 donations in just 10 hours. Now this donation drive was a last-ditch attempt to keep the company afloat, since it was millions of dollars in debt before Pulse 87 even launched. Even if they were allowed to continue soliciting donations over the air, that money wouldn't have lasted, and they would have had to do another fundraiser within a few months or shut down.
The fact that so many people donated shows that people will support whatever they are passionate about, even though they played commercials between the pleas for donations. There are hundreds of Internet dance stations I can get on my phone, but I chose to donate to Pulse 87 because they were local and had an impact on the nightlife scene in New York City. Since I had almost exclusively listened to 87.7, I felt like I had to support them financially.
If you feel like the station you're listening to does a service to the community and offers music not available on other stations, by all means donate. If you think it's nice to have around but don't listen to it every day, donate a little to help support the station. If you listen to it for hours a day, definitely increase the size of your donation to show how much it means to you.