It all depends on the "quality of the post being upvoted" and the "amount" you have sent to the bidbot.

The "main" purpose of bidbots is to increase visibility of a post. If you are only sending 1SBD then for sure it will not even reach the "hot" section and no one will be able to see the post let alone have a chance of being upvoted by others. Most likely it will be drowned along with other posts after 5mins of being upvoted by the bot.

The next thing is "quality of the post", if your post is good enough then the moment it reaches the "Trending" or "Hot" section , chances are more people will see your post and will likely upvote it. The downside of course is if your post is of low-quality then instead of being upvoted, you'll be downvoted.

More visiblity = More chances of being upvoted = More profitable