One of my eMail addresses is being hit a few times a day by Share Price spammers.
They don't want to sell you anything per se - they want you to buy penny shares in a company that they have selected and are now "hyping up". If enough people do then the share price moves and they make a profit on the shares that they already bought.
And their spam is pretty sophisticated - they put everything in an image rather than text and send from random eMail addresses / hijacked IP addresses so very difficult (impossible?) to effectively block
RC