Doing creepy psychological profiling to sell me ads for a few extra shekels? Very dodgy.

Doing creepy psychological profiling to find matches with traits neither party would otherwise voluntarily disclose on a public profile? I mean, yeah, sure.

It's not the case that people are concerned over Facebook having their innermost desires stored on some server somewhere, although they like to pretend so. The issue is more along the lines of whether natural persons they interact with IRL see them - this is why people are OK with using Tinder and Facebook messenger, but not with having private conversations over Twitter.

Of course, they'll use the profiling for both. But the end user arguably extracts more of the value than they do from getting sold more relevant ads.