Being in profit is a difficult task when using a bid bot. I have realized it is better not to bid a large amount because you then have to watch for the price of Steem. The bigger the value of your post the faster it will go down if the price of Steem falls which is almost 90% of the time. Anywhere from 20-30 in rewards is perfect.
Thank you for your comment @deniskj. I always splir my bids with 4 bots or 5 so if one does not so well it doesn't matter. The value of STEEM going down is a concern, but I do nit look at that for my bids. I put 20 SBD on each post and the avarage profit in additional SP gained is always positive when calculated on 30 days.