Asking the question "Which is more important, the mailing list or product?" Any savvy marketer would reply "The mailing list".
The importance of hungry demand, and not just any demand, is what wise business people place before the product. In other words, a product is useless if there isn't a demand. A mailing list is a representation of the demand for your product or business, if you wish to call it that. You can read: Is email marketing effective?
You will notice that service and product owners require mailing list owners more than anyone else if you visit the Joint Venture forums or any other membership site. Because the mailing list owners are able to reach the potential customers that each type of partner is trying to sell to, this is why.
You don't have to make money selling your product if you own a mailing list. In return for commissions, you can either sell advertising space or create a Joint Venture.
Today's most successful web businesses often start their mailing list (or subscribers) before they launch the product. Friendster.com is a fine example.
Friendster.com is a website that allows you to connect with friends and potential friends around the globe through a free membership.
Friendster.com doesn't make any money from the number members who sign up, but the company does make money by selling advertising space and partnering other big-time merchants and businesses. This is due to the large number of Friendster.com members.
This is a perfect example of why every business needs to establish a demand or need before it produces a product.