We stopped advertising on Facebook
I think Facebook is making mistakes.Adwords grew explosively, but relative to the expectations of Facebook, Google looks patient. Adwords didn't start off with ten million customers with endless budgets. They started off letting people buy $20 worth of ads at 5¢-50¢ per click. Some people figured out ways of selling ebooks or whatnot at a profit and figured out things like split testing, conversion tracking and such. They were then qualified to be consultants and go door to door to electricians or removalists who got a good ROI and eventually allowed the consultants to spend an extra $350 per month. Then they hired an in house 'PPC Specialist' who spend their week figuring out new ways to profitably send Google more money. A lot of the campaigns set up 5 years ago are still active. I worked as a consultant back in 2007  and most of the campaigns I set up are still running.It took some time to figure out that Adwords works for dentists but not for burgers or detergents. That wasn't immediately obvious. Burgers and detergents were the big spenders of the advertising world and a platform that didn't work for them was a toy.There were a lot of ultimately stupid campaigns started. Half the initial customers tried to get a better CPM (cost per 1000 impressions) by optimizing for a low click through rate, benefiting no one. Google killed this off by creating adrank. The other stupid advertisers were eventually outcompeted by those who could turn their click into revenue more efficiently.My point here is that Google put a tool out there. It took time before users (advertisers) were good enough at using it to put pressure on the bids and bring up prices. Someone figured out how to sell car insurance. Comparison sites were created. They signed deals with insurance companies. Ecosystems developed.Facebook ads aren't useless. They just work for some stuff. The advertisers just need time to figure out what works. If you are having a town fete and want parents with small children to know you have a petting zoo, Facebook ads will get you customers physically driving to you for cents. Incredible value.Facebook is just impatient. They keep moving the posts in an attempt to find a formula rather than making good tools, leaving them out there and letting advertisers find the formulas.