A direct mail marketing solution for curbing the direct mail cost is to purchase a bulk rate or 3rd class rate; if you can afford the bulk rate time delay, then you will save up to 70% on postage costs for your direct mail letters. An excellent direct mail idea is to use 3rd class stamps rather than have the direct mail metered--the former makes for a better image, increasing the direct mail marketing benefit.
It is advisable to take a sample direct mail package to the post-office to make sure the direct mail processing goes through without a hitch. You may also want to employ a direct mail house that sorts.
Lastly and most important, make multiple hits!! Follow up direct mail letters with telephone calls, faxes, emails and direct mail post card reminders. Make up the consumers' minds for them.