DadJoke007: The question is: does this PR have a net positive or net negative effect on long-term profit?
It might be a mix of both, leaning maybe slightly one way or another and shifting over time)
DadJoke007: I wouldn't be that enthusiastic about customers using the community page of the store to band together and encourage shopping from the competition instead.
True, still if they tried stamping such out they'd likely lose even more business.
DadJoke007: There are always more people who observe than participate in discussions, so there are tons of potential customers that can be swayed by the negativity regarding the store.
That is somewhat fine, imo, if a store has warranted that negativity & the shift in buying from said store might get them to change their ways a bit.
Also even if they didn't allow such talk, people would do it in private or on other sites.....the streisand effect, etc.