But CPC, well I've never clicked on an ad on Facebook in my entire life.
Otherwise, even google would be out of business.
You literally type into Google "I have this problem" and get a bunch of ads solving that problem. It is practically the holy grail of advertising. Now consider that it is a catch all for personal and corporate questions, it is a cash cow. It is perfectly acceptable to google something at your job, click on a link, and buy a $15,000 system.
Facebook might know a lot about you, but they don't know what you are looking for at any given moment. Add on top that most people are spending their time on personal relationships, and it isn't the same even if they get more impressions. I can't log into Facebook from work and say "who has 5" diameter pipe?" and expect a response, but if I google that I find a vendor and place a multi thousand dollar order.
Also the market on Facebook is somewhat inverted. The "best" customers are generally on their the least. The most frequent people are college students - mostly broke at that. If you aren't advertising clothes, personal electronics, or local bars I don't see the draw.
Google ads work when there is so-called "purchase intent": I know I want a new waffle maker, so I search for it.
Facebook ads work when there is demographic correlation: I just got engaged, and I might not know that I now need a waffle maker, but a Facebook ad can target me and tell me that I should be adding a waffle maker to my wedding registry.
Different kids of targeting, both extremely powerful.
And seriously. Waffle maker. It's the gift that keeps on giving.