Today's automation enables us to run our internet radio stations' unattended. This is a great thing but remember, your audience can get bored. You should "freshen up" your station from time to time. Make some small changes like adding some additional music, changing up the rotation and/or the imaging liners, jingles, voices etc. on a regular basis. Your station will be more interesting to listen to without a major format change. It's the same as hearing or seeing the same commercial over and over and over. You do get bored. Any little change can spark the audiences interest without them ever knowing it.
A good time to freshen things up is after the holidays. At Edgewater Gold Radio, I'm not making any major changes but will be changing the rotation a bit. I've upgraded the station ID and will be making some changes to the night time rotation.
Remember, a little can go a long way as far as listeners are concerned!