Hi @martinphoto, pasting my answer from the second question :)
Please remember that voting bots are not for printing money - otherwise everyone would just make spam posts and use as much voting bots as possible, because you will earn anyway, right?
Voting bots, as I see it, are for promoting your post - gaining visibility so more people can see your post, see it's value and upvote it.
Currently, using @tipU, spending 1 USD gives back 1.1 USD (and proportionally to higher upvotes) in both SBD and STEEM POWER combined, so technically you're not loosing money but you can easily print SBD either.
You can test the post rewards distribution here: http://steem.supply/rewards
Hope this helps :)