So I've used @smartsteem to buy upvotes for a few of my posts and it seems like a wash. Unsurprisingly, you'll make about as much as you put in, or a little less. I really don't see the point of using the service unless you are willing to pump up a post high enough to make the trending page. Even then, you risk angering the Steem gods and getting flagged. However, it may have one more use that I'd like to test out.
I might not be able to profit much from @smartmarket, but perhaps I can use it to support my supporters. I think I can use upvote services to manipulate curation reward payouts. If I wait for my followers to upvote my post first and then buy votes after that, they may receive a good amount of artificial curation reward while I break even. In turn, this would also leech curation rewards away from people selling their votes. Win-Win.
My understanding of how curation works is quite limited. I'd like to test it out with this post and future posts. If I can get an upvote from say @krnel and @taskmaster4450 or even @wesleybos or @troglodactyl I think that would be enough to measure how curation gets spread around a little better.
Part 2 of this test will come in a week when everyone gets paid out. I'll be able to measure where all the curation went and see if this manipulation is worth it. If this post doesn't get enough upvotes I'll simply have to wait until one of my posts does. I'm going to have to test multiple posts regardless. I figure I'll have to track one post that was $2 before the pump, $4, $6, $10... whatever I can get.
EDIT: I've been paid out but the option to edit post remains.