The average click-through rate for Facebook ads was 0.063% in 2009 and 0.051% in 2010. Click-through rates used to be about 3% in the 90s, but have been declining since. Current industry standard is 0.1%.
I heard that facebook is good for awareness, just to let low- or no-paying people know you exist, but click-through rates are pitiful, indeed.
CTR has declined since the early days but profitability has really increased. Check out some of the ad management tools if you're having trouble - they can really help you get into the data and find results :)
