That's an interesting question. Interacting with people in an unsolicited manner is very hard from a legal/ethical standpoint, so using a method like this to "r

That's an interesting question. Interacting with people in an unsolicited manner is very hard from a legal/ethical standpoint, so using a method like this to "reach out" wouldn't fly. On the other hand, user education about the profit motive is certainly something that could bear fruit, and so the first step to educating them is figuring out what the numbers look like in the first place :). That's what we're up to, and trying to find ways to keep spam from being profitable is something we took a look at in our upcoming paper at this May's IEEE Symposium on Security and Privacy.