There are two important points from a psychological perspective on buying and faking friends, followers and likes. First, that this kind of thing demonstrates either some level of hubris or stupidity that the transparency and access of social networks wouldn't expose such actions. You don't get the lift of exposure on the upside without the scrutiny. A lot of grandma's rules of social behavior translate well to social networks, such as don't gossip in crowded elevators, or, in this case, make sure your underwear is clean.
Second, research on social persuasion (notably Cialdini) shows that we assume something with more attention, friends, customers, etc. is better. We are hardwired to this cognitive bias, a hangover from our evolutionary behaviors such as knowing which berries are safe to eat. It is an unconscious response that guides our behavior. When we find that we have been tricked and manipulated, it destroys trust. Not just about the event in question, but about the character of the person we trusted. It violates a social contract. We can frame this in terms of other cognitive biases too, such as the 'just world' bias, in which we believe that things should be fair, which is why we like to see the bad guys get their come-uppance and the cheats get busted, and the reciprocity (or tit-for-tat) response in which we inherently keep track of social exchanges, favors and behaviors. If you cheat me, it changes the nature of our relationship. It destroys any 'obligations' from social exchanges.
While seeing lots of likes and friends on Facebook might make Hillary Clinton more appealing by offering 'social proof' of her as a candidate, the damage that would come from questions about character, trust, honesty, judgment, and fair play, not to mention any feelings of payback from being psychologically manipulated (i.e. unconsciously tricked) can seriously damage social capital between a candidate and supporters.
Hello? None of this stuff is a secret. With all the money spent on marketing and psychographics of big data, are there no media psychologists on board to look at the relational impact of social media?