As someone who has run FB ads since the beginning though, I would disagree with one thing: in my experience over the years, people are ok with leaving Facebook, so long as you have a very nice, clean, easy to understand page with a clear value proposition.
My suggestion going forward is this: 1. Take each winning ad and make 3 more variants. 2. Take each interest you were targeting, make a separate campaign for each. 3. Place all variants of your winning ads in each campaign.
The purpose of this is to find which actual interest is responding to your product. Once you find that out, refine it again by breaking up location, age, gender, education, etc.
Get really granular over time. The end result is very good ROI and a solid way of making money on FB :)