This works every time:
Save self addressed postage pre paid envelopes you recieve from junk mail distributors. Place other junk mail and/or coupons in pre paid junk mail envelopes for things like "Buy Two Hams, Get A Cornish Game Hen 1/2 Price", "Book this vacation and get a free wristwatch" or "For every two tanning appointments get a third FREE"
The wackier the offer, the better! Just nothing vulgar or pornographic.
It works like magic! Suddenly the junk mail stops and the companies never send you anything again! I love sending them back junk mail at no cost to me!!