Typically with FB, you are doing well if you are finding anything near 0.05% CTR. Remember, these are content ads and not paid search.
Paid search you should be hitting 5%+ CTR on your top search keywords (in position 1-2, around 3% for #3 and 2% or less for anything below). On FB, getting an ad with a consistent 0.077% CTR means they are on to something and should keep going.
Don't knock FB off your list of advertising venues though. Each one is different and has a completely different dynamic, approach to users and value proposition. With paid search you bid on user intent through keywords - what they are looking for right now. On Facebook you are bidding on people and trying to get their attention, a big difference :)