Pandora is all new and is celebrating by giving a 90 day free trial. (or 60 days if you just go straight to their website).
Here's how I got the 90 days:
I logged in to my yahoo mail.
In yahoo mail, I scrolled down through my mail about 1 page down and saw an Ad that said Pandora 90 days free. Click it. A webpage pops up with a video. Under the video, click "Learn More" and it goes to a Pandora page that lets you sign up or log in to get 90 days free premium. After 90 days it is $9.99 a month if you keep premium or you can cancel and switch to the free service.
If the Ad in yahoo mail is different or changes just reload the browser page until the Spotify Ad comes back. I just had to reload twice.