"The kind folks at the NYTimes sent me a letter in the mail today asking me to subscribe to their newspaper. Any response suggestions?"
Did they include a prepaid response envelope? If so, stuff it as full of junk (cardboard from soda 12-packs cut to letter size works well) as you can and mail it back to them. The heavier the letter, the higher the postage due.
I do this all the time with those pesky credit card offers.
Brilliant.