Questions concerning "SPAM?"?

I get a lot of SPAM sent to my email, the advertisers got the email address so they sent to it... Got it, that's how it works. I mark the item and send it to the Mail Box SPAM Folder, this is suppose to permenantly mark that addressee as a spammer... I have had almost 1000 messages in my inbox, many of them duplicates of others from addressees that should have been marked as spam... What gives here? There is no reasonable explanation for these repeat messages from the Spammers. Please assist in fixing this nmatters