Well I get spam with their names and advertisements on it, so somewhere in the chain of events they are making money from that spam.

I just call them and let them know that they are not ever going to make any more money from me.

They are at the head of the chain and if people let them know it is going to cost them, then they will stop.

So please write to the boards of those companies in which you own stock and let them know that spam is costing them customers.