When my grandmother died in 1999, I was named the executor of her very modest estate. I closed down her accounts, shut down her few credit cards, paid off her accounts, and cancelled her newspaper and magazine subscriptions. I assigned my address to her estate and had per personal mail forwarded to me so I could correspond with the various banks, credit card companies, and merchants for closing her accounts.
The only thing requiring more than 30 days to wrap up was dumping a worthless piece of undeveloped property in the middle of nowhere. By the middle of 2000 everything was complete. I figured the only thing left of her were my memories of one of the nicest, sweetest little-old-ladies you could ever meet (which is why the first Christmas after her death I literally had to write dozens of responses to Christmas cards, informing people to take her off their yearly list).
Five years after her death I find that she has achieved a sort of modern day immortality through the mass mail system. She receives credit card offers, requests for donations, and even an occasional newsletter from a hospital or charitable organization. Being the kind-hearted woman that she was, she gave modest amounts of money to various charitable organizations even though she was on a fixed income from her pension as a school librarian and her social security. So she became a fixture on the charity mailing lists.
The first few times I received these I wrote quick letters back telling these organizations that she was deceased and to remove her from their mailing lists. The mailings slowed down and then stopped, but six months later new mailings started to show up again. I initially responded to these as well, and things stopped for another year, then new mailings showed up again. I went through this iteration a couple more times, but after a few years I just gave up. It is now a very slow trickle, but half a decade after her death she still gets something addressed to her once or twice a year.
Turns out you not only stay on the mailing lists after you pass on, you get on them before you are able to read. Last night my daughter, who is three years old, received a credit card offer. I figure 100 years from now whoever is handling her estate will still be getting these offers.