Publishers know they can save a lot of money joining others in joint or cooperative mailings. Co-op mailing is not a new concept or idea, but finding other publishers who want to mail to the same lists isn't easy.A free service is helping publishers sell more books through cooperative mailings with other publishers. Publishers submit listing information, as to what kind of mailing they want to do, the nature of the books or items they want to promote, and contact information. DVDs, audiobooks, CDs, software and other items work easily here too. The information is published each month free in a newsletter for entrepreneurs and publishers - 'Helen Hecker's Biz Hotline.' We ...