Definitely giving it to a bid bot is more profitable for a person, but in reality it doesn't help Steem much, hardly anybody gets a profit from bid bots, and I can only think of 2 positive things about them: If you bid for at least 50 SBD you will probably make your post very visible and can probably get some good rewards, the other one is that these votes do add up to increase your REP. So I think even though your approach makes you lose money, which is something very important, you can make up for it knowing you are doing something worthwhile, becasue delegating your SP makes the person who got it to start upvoting, this means the rewards are more likely to be spread among a lot of people which I think is the right idea.
I agree and have used them for this purpose in the past. A little hypocritical of me of course, but this was due to a post I read that stated that if the good authors don't use them, the crappy posts will rise to the top!
I'm paying for my sins with these delegations :)
Thanks for the comments!