Well, we can look at what was said (in the third-party retelling):

>Grace had the gutsy idea to ask the bouncer to make everyone who came into the bar have to vote for Watsi on the contest site on their smartphone

I agree that it might not be quite slavery (it would depend on exactly what happened), which is why I included tribal exclusivism, which it most certainly was (at least according to the above portrayal).

Edit: Anonymous down-voters are out, in-force, tonight!