The first thing is not true for many sorts of spam. For example a lot of the people who destroy google search results do it manually and even pay for domain nam

The first thing is not true for many sorts of spam. For example a lot of the people who destroy google search results do it manually and even pay for domain names tp do so. It is more difficult but I would say only slightly more so. And worst of all it is likely that spsmmers are willing to pay a higher price than your genuine users. Spam can be highly profitable. That they make you a profit is true though, but that is both good and bad. It finds your antispam work but could also create perverse incentives where you want spsmmers.