I tried out Google Radio on their 30 day free trial and found I really like it, but I also came to realise I can't afford to spend $12 a month on a luxury. I looked at the alternatives and decided to try out Pandora. Somebody had already registered an account on it using my email address, but it turns out it was easy to take it back by changing the password. It looks like whoever they were had abandoned the account some months ago anyway. At least their musical taste wasn't limited to the top 40. So if somebody called kangaroos06 had previously insulted you on Pandora, please be assured the rebranded Marko Rat is not like that. ;)
I am pretty pleased with Pandora so far. Its ability to pick musical sounds based on a band seems pretty good. I accept the price of a "free" service is advertising, but so far there hasn't been much. There seems to be no advertising when listening to music on the web interface and I've only heard one advert in the audio stream. There seems to be a lot of advertising on the Android app, but that will mostly be in the car when I can't look at it.