The title of this post is taken from a search string that brought a reader to this blog. It's an interesting question to ask of Google. How do we answer this query? Well, we need to know when we see a bot and to determine what it is up to.
Often you will see bots on a horse race order book as soon as it appears on Betfair. The stakes will be low, about £2 or thereabouts and odds will be very conservative. Either very low or very high. As soon as someone makes a better offer the bot will jump ahead in the odds with an even better offer and so on, until the bot's offer is taken.
Obviously these bots and their low stakes are programmed by a novice bot trader with no real understanding of betting markets. The bot will either be offering to lay at very low odds or wanting to back at very high odds. The bot has no idea of fair odds for the horse in question, it just wants to get matched as soon as possible before the spread closes.
As soon as the odds are matched the bot will then try and reverse the position on the other side before the spread closes. If the bot owner is lucky the bot will find someone stupid enough to take the odds whilst the book is at over 200%.
These simple bots will never make the owner wealthy because the average bettor is not so naive to risk large amounts of money whilst the overround is so big. Also, there is no point trying to outwit one of these bots when it is offering peanuts. A more sensibly coded bot is one that does repetitive or simple tasks for a knowledgeable player. And then, you may as well treat the bot as though it were human because it probably isn't going to make a serious mistake.