Bingo! I purchase a lot of online ads, and I can tell you, I give nearly all my ad budget to Google. I tried Facebook for a while, with the exact same ads and the exact same product, and the result was shocking. Nearly 10x less conversions than with Google. I think the reason is simple. Google users were already searching for me, facebook users were just bored looky-loos. When people start to realize this about fb it could be the short of the century.