It's a free service lol, and people are free to use it, not use it, or leave at any time, it's not like that can possibly be a scam, even people who never ever let their accounts go idle (which is when the bot votes, it only uses unused power before it gets wasted, always has) use and appreciate the community and the service

On this very post is an example of another value added service, one that you didn't make any accusation of, they are equivalent, in fact SOM has a longer track record and is more trusted by its users.