I thought it was much, much less than that tbh. I expected they were earning like $6.53 a month or something. $30 I think is pretty decent. No, it's not a huge amount of money in the grand scheme of things, but it's some decent pocket change for taking a few minutes to spam a couple of links every day.
Plus, bearing in mind what I know about the level of brokeness of a lot of niggas on here (plus, my conviction that a lot of these people are teenagers) 30 bucks can make a significant difference for some of these cats.