I have never seen the bid-bot on the tracker produce positive ROI. Last minute indiscriminate bidders send their SBD putting the ROI negative 20% usually. The bid-bots can still be useful as a promotional tool to get you exposure and hopefully organic votes.

You can try buying upvotes directly from bots like MinnowBooster which has a stated return based on availability. Although even this I have not been able to find evidence of profitability especially since SBD is not equal to $1 and I believe the bots use $1 as their base figure.

Best of luck. Steem On.