Yeah, this is even something you really do not have to do so much depending on the campaign and you get paid for it, and if you are lucky to hit the right project most of the time with great demand and product, that would even make it more interesting for one in the long run.

I would not consider it a waste of time and for those who do, I can assume the pay may not be that much, but there are other forms of campaign with more skills one can join to get the best from them.