Buy upvotes - is not a profitable business?

Hi everyone! I did my little experiment, and I found that buying upvotes at https://steembottracker.com - is not a profitable thing.
See for yourself: I paid different six bots in total 1.66 SBD, and got only 1.458 SBD and 0.378 STEEM POWER.
It turns out that I even went into a small shortage.

0.25 SBD to Hive account@levitation

0.14 SBD to Hive account@minnowvotes

0.30 SBD to Hive account@kittybot

0.70 SBD to Hive account@minnowhelper

0.10 SBD to Hive account@mercurybot

0.17 SBD to Hive account@adriatik

Why did this happen? Why there is no benefit from their upvotes?