Remember "Follow the money?" It seems to work for spam, too.
I still get questions from people about things advertised in spam. Is this legit? I tell them, no.
If no one bought from spam that would shut it down, too. Sadly only a very, very small percentage of people have to buy from spam to make it very, very profitable. So barring people suddenly getting smarter, if we could shut down the banking end of it, it might help. Then again it might just be another form of whack-a-mole.