Database is a collection of information may it be of your consumer, client or other vital information for marketing.
As a person who has been into market development, we rely much on consumer mailing lists bought from suppliers like LIST Company. Companies like them are also called list brokers for their ability to negotiate and look for compiled information necessary for market competition.
Marketing list is easy to search if you have a company such as List Company backing you. It's database boasts around 14 million United States businesses and companies and another 300 million US consumers. I think, this is so far the largest database that any company can boast perfect for your promo collaterals direct mailing and telemarketing needs.