So essentially $1100 for ~600 likes, I certainly wouldn't be happy with that return. It's an informative piece but I think your summary is a bit off regarding the campaign a success generally.
I think by simply joining Facebook groups in this sector and engaging with the group you could've achieved 600 likes in the same timescale and saved yourself the money.
Targeted likes or just likes in general? There are folks on Fiverr who can deliver untargeted likes at 10 cents a pop (which might be useful for the initial social proof). No idea how they do it but I tried as an experiment and they don't all look like zombies.
That seems really low for me. The only way we could have done that would be to use low value inventory like from developing countries, but usually the advertisers had a certain demo that they wanted to reach and that raised the price.
Yeah, the demo is probably not good at all. But in terms of building up a few hundreds likes in order to get social proof for later folks, it's an option at least.
I think by simply joining Facebook groups in this sector and engaging with the group you could've achieved 600 likes in the same timescale and saved yourself the money.