NetCreations, Inc., one of the leading providers of 100% Opt-In email marketing services, today announced that its PostMasterDirect.com database has topped 20 million double opt-in email addresses, more than doubling in size since June and quadrupling since November 1999. NetCreations' PostMasterDirect.com database is currently growing at a rate of more than 80,000 email addresses a day from the NetCreations network of more than 380 partner sites, including About.com, internet.com, Entrepreneur Magazine and GroupLotto. The database is made up exclusively of double opt-in addresses belonging to Internet users who have requested promotional information related to specific topics of interest and verified their request by replying to a confirmation email.