Not that i approve/disapprove of this sort of thing but i think you need to change your bot specs a little. This could be useful for businesses if it bumped a thread after say every 3-6 hours of no replies. Altcoin services would really utilize this as that section is crazy.
Yes, i must say that this bot can be useful as if it involves no human interaction. I wonder if it is auto, is it allowed on the forum the bot posting itself ?
Personally I would not buy with this system, it is good to see some threads that are bump due to some serious interactions of the members themselves and not just a simple bot to do that task, but anyways that is just my opinion and I don't think there is something wrong with the service.