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There are a few bots out there that will either move you into the next voting window or refund to keep votes profitable, but you have to specifically look for them. Steembottracker should put labels on the ones that do much the same way that they do for informing users that the operators keep a portion or post a comment in your post.

wow - wasn't aware of that. Do you know which one? Care to share with us? Someone already mention smartsteem. If there's more, would be good to know. How about Minnowbooster?

I don't remember which bidbot it was. I just remember it happening to me last week.

Minnowbooster is slightly different. I think, and I may be wrong, but you're not bidding, you're just straight buying them from people selling votes. I think its a more or less fixed return. From experience the return is about equal or a little more to what you send them split between SBD and SP. I've only ever sent them .5 SBD few tiimes. Smartsteem is the same but they also have a bidbot.