Broken ? Rated 4 out of 5 stars

Hi - same here. As of a few days ago, this doesn't work anymore. I am running firefox 3.6.13 on Win 7 - 64 bit. Hope it works again soon - deserves 4 stars (based on past experience)

This review is for a previous version of the add-on (0.55). 

Bit.ly credentatials required

Bit.ly is no longer allowing calls to its API without login credentials hence this issues. You will need to create Bit.ly login credentials on bit.ly website. Please enter bit.ly login credentials In Add-on -> Shorten URL -> Options.
With this the add-on works as before.