Steemit voting bots are clear scam, don't use them. I was aware of that for a long time but I wanted to test it myself.
Results are here:
Spent: 20.50 SBD
Received after 7 days: 13.56 SBD, 4.04 SP
In the last time too don't lucky with bots. My result:
Spent: 37.50 SBD
Received after 7 days: 18.75, 6.27 SP
Need trying something other for promote.