Fitbit is great at motivating you to go the extra distance once you are out and about, but not so good at motivating you to get your ass off the couch if you've got nowhere to go.
The issue (as we see it): there is no threat of punishment for not reaching your goals.
Now there is.
halfstep: music that moves you.... literally.
A chrome extension that looks at how you did against your Fitbit steps goal from the previous day, and then only lets you listen to the equivalent percentage of each song today.
Only hit 70% of your goal yesterday? Well, we hope you haven't grown too accustomed to the ends of your favorites songs... because you won't hear them today because you won't hear them today (but you will get some "motivational" notifications).
Maybe tomorrow will be better, you slacker.
Currently supports Rdio, Pandora and Hype Machine (sort of).