Yes they do offer upvotes - the one that I tried I got an upvote of nearly $0.30 which aint to bad. However, I do feel they dont really add value to the blockchain and are just clogging peoples feeds. I decided after posting 1 to "boycott" them as I dont really think many others are interested.

In saying that they are a good way to get some more exposure for Drugwars, I do agree!