It's a tough effect to analyze effectively, given how indirect and disconnected the effect they're aiming for is from their ops. But the thing is, they're really, really cheap in relative terms. With the ones run by nation states, even a minor return is going to be an infinitesimal part of their budget with very little risk to them. Even minor successes would be more than sufficient.
I mean, the Army funded the Stargate Project[0] for nearly two decades. Social media ops have at least an advantage or two over staring at goats.
0. https://en.wikipedia.org/wiki/Stargate_Project