I've always liked the idea that bidbots would ultimately end up being the advertisers. The reason is that its cost-effective and sometimes even profitable for the person promoting their own product, while also being profitable for the bot manager. Increased visibility and shared profit is something I like the idea of and think its an innovation over Facebook ads.

But I suppose there is nothing wrong with traditional ads being placed somewhere on sites. At the very least, we shouldn't cultivate a culture of thinking it is somehow wrong. It has nothing to do with ethics in anyway, its just one way to monetize a business.