Originally Posted by MaxwellSmart
While FB PPC can be cost effective (realitively inexpensive compared to Adwords for instance with great demographic targeting), one word of caution...
Facebook ads because they are passive advertising (similar to Adsense where people are NOT really searching for that which you're advertising) instead of targeted advertising (like Adwords where ads relevant to the user's search phrase are shown), Click-Thru-Rates will generally be very low.
And Facebook ads suffer from a unique phenomenon called "ad fatigue". The first 2 or 3 days your ad runs, you'll get a decent CTR... But after that the ad's CTR will drop off significantly each day. Within typically 5-7 days you will get virtually no clicks. People simply begin ignoring the same ads they've already seen.
So one key to advertising on FB is to change your ad copy (and images) every 3-4 days...
From my experience, it is very unstable and really depends on your nishe.
A lot of ads ged disapproved. CPC at times is enormously high.