I haven't done a lot of FB PPC but for some reason I've always had the impression that a CTR of 0.8% was minimum or you should scrap the campaign as it's not doing well enough. Or is it 0.08%?
The limit set (i believe) by FB is 0.003%, but you won't get anything great off 0.03%
0.8% is an exceptionally high CTR for a a campaign....