Companies who provide these services are not only out to make a profit - but they understand the difficulties of direct marketing to a market mailing list that is less than likely to buy. Once you are entrenched into a market that is more than likely to buy, you will see more and more leads come in that can be transformed into sales dollars with a little dogged yet polite persistence and the all important follow ups.
Speaking to someone who has a greater chance of wanting that service or special feature will more than likely make them either have a 'buy now' or 'I'll think about it' attitude - which everyone knows in the grammar of selling - is a window of mailing list opportunity like no other where leads for business are concerned. Anyone who is either striving for success in direct marketing or thinking about going into it should seriously consider mailing lists - it is the difference between success and failure.
Whether you work in a brick and mortar building, or your business operates solely on the World Wide Web sitting on the servers of a hosting company, customers are your life's blood. There's no getting around it. Everyone has customers when in mailing list business. You're either offering a service, in which case your customers are coming to you to fulfill a need, or you're offering a product, in which case...oh, that's right, your customers are coming to you to fulfill a need; Funny how that works.