After a few years of pandora, my stations all have thumbs up (or down) and I've added variety to each one and they are pretty much spot on with how I want them.
What kills me is like what just happened earlier today.
I had some hard-core paperwork to get through, stuff that's boring and I've been putting off for too long. So I closed my office down, shut off the lights, put on my headphones and cranked up my Rob Zombie station. I'm rocking out crushing the paperwork and right after Living Dead Girl it goes into a Home Depot commercial. Talk about mood killer.
At least its only 30 seconds and only every 6-10 songs or so.