There are two significant disadvantages/annoyances of Pandora if you use it on a laptop in a window:
1. Ads
2. Are you still listening?

To hack the first, just use AdBlock plus (a Chrome, Firefox extension), and uncheck “Allow some intrusive advertising”. This should take care of the annoying ads.

For the second, the workaround is slightly complex. You will have to install Leechblock if you use Firefox or Nanny if you use Chrome. The trick works because when Pandora goes “Are you still listening?” the URL changes to http://www.pandora.com/inactive
In the settings, do these things:
1. Create a rule to block http://www.pandora.com/inactive
Set the rule to run for 0000-2359, and do step 2.
2. Search for the “redirect to” URL and put in the station you listen to on Pandora (or just https://pandora.com since it would recognize your login and work properly). You should be good to go.

Two irritating features removed that would make Pandora pure joy, as it should be. Needless to say, these work only on a computer (no AdBlock plus on Android yet! Boo!). But if you are using Pandora even on your phone, just pay up. The charge is hardly much.