Pandora remains one of the most popular streaming music services around, but most users are still on the free, ad-supported plan. If you are traveling to Groupon today, you can get three months of premium listening for free.
The Groupon deal actually lets you choose between three premium options, all for free: three months of either On-Demand Premium, On-Demand Premium Family Subscription, or Pandora Plus. Those subscriptions are normally $ 10, $ 15, and $ 5 a month, respectively, so there's really no reason to go for the more expensive one unless you think you might want to stay on it.
Pandora Premium offers pretty much all the same features as Spotify's paid accounts: playing any song directly instead of using the randomized radio, custom playlists, downloads, and unlimited ships and replays for stations, and no advertising. Pandora Plus does not have access to on-demand songs or playlists.
Groupon says that the time for this deal is limited, but doesn't give a specific expiration. Go for it today if you want to get in.