Ask HN: Have you tried Facebook advertising?

Have you ever used Facebook advertising? What were the results (CPC, CTR, conversion, frequency)? How does it compare to other advertisement platforms you've used? What tips can you give me for effective low-cost campaigns? OP starts: I used it once for a survey. I spent $100 and received 109 clicks for that money (CTR 0.008%). Those 109 clicks resulted in 13 completed surveys, so a conversion of 12%. The frequency was 7.0 with a reach of 207840.

To be honest I was really disappointed. I expected a higher CTR (more like 0.01 or 0.02%) and a lower cost/click. It cost me nearly $1/click while I counted on $0.25~0.50/click.

I'm planning to use Facebook advertising again though, the geographic targeting is pretty good. Looking for some tips. Should I go for a higher frequency (Seth Godin says that frequency > reach in his book Permission Marketing)?