Another problem and reason for getting spam is spyware installed on your computer without your knowlege. Spyware reports back to the spamming company you web surfing habits and thus the type of advertisement that might interest you. That is why, for example, if you are searching for information on retirement programs you start getting the Viagra ads. I use a program called Spybot Search and Destroy to find and remove spyware, it's free and it works. Just Google the name and you'll find a download site.
I changed ISP's to one with a spam filter and never get spam anymore. I was getting about 30 messages a day before. Hope this helps.
