[gadders]

Dumb question, but is there anyway you can contact uninstalling customers to find out why? Could the plugin pop up a comments form asking why people are uninstalling that gets to you and your colleague?

I think customer feedback would be a good starting point.

[samanamp]

Since your comment, I've started contacting them one by one with a personalized email. I think it takes some time to found out what exactly to write to get them to respond; yet to get any response.

[Nicholas_C]

This is my suggestion as well. Send surveys and/or personal emails to folks who uninstall and try to find a pattern - it could be a simple tweak or feature add that people want.