I know (from my own experience) that the work you put in to make this blacklist available is incredibly time-consuming, and doesn't even benefit you as a promotional service. As you've mentioned, from a financial perspective, spammers are our best customers. And rarely do you even get a thank you for researching these users.
So I thank you for making this available for all bot owners to use, and I hope more will decide to use it. It's an invaluable resource and if more of us simply plugged this in then we could really put a huge dent in the abuse here. Keep up the great work. It's exactly why you have my witness vote (oh, and the fact that you run 4 full nodes!) :)