If someone wants to leave your mailing list, there is no point trying to hold on to them; they have already made the decision not to buy from you. To give one last professional impression of your business, you can at least make unsubscribing from your list easy and straightforward. It is ethical to include an unsubscribe link in all your ezines, and this should link to an automated system that will remove them quickly and painlessly. Wish them farewell and get on with providing quality content to those who do want to receive it.
For lots of advice and free tips, check out the FREEBIES page at the VA Success Group