Fly Fan - Does it really work?

I first saw these fly fans at Ikeda's pie place. It did keep the flies away but it was also a toy magnet for the boys. 

My niece (who likes to shop on Amazon) thought they would be helpful on our camping trip. We really didn't have a lot of trouble with bugs but I think it did help when we were cooking bacon. During the day it worked well but the night bugs, not so much.