E-mail marketing works, there's no denying it. Its key advantage over other Internet marketing methods is that it enables you to contact customer instead of forcing customer to contact you. This ability is especially useful when something that your customers need to know as soon as possible has happened. Whether you've just released a new product or decided to cut your prices by 10%, fastest way to spread word is via E-mail.
However, unless you want to give your company a bad name, you can't simply start sending E-mails to people that haven't agreed to receive them. The only ethical and reasonable way to advertise via E-mail is to first obtain a permission, or an opt-in request, from receiver. The trouble is that this can't be done via E-mail, as it would be similar to asking someone whether you can ask them a question. What's point in doing that, when you've already done what you wanted them to allow you to do?
Getting people to opt-in ========================
1. Arrange a sweepstakes with an attractive grand prize, for example one of more expensive products sold on your site. Require everyone who wants to enter drawing to give out his E-mail address and agree to receive occasional E-mails from you.
To get best possible results, it is advisable to declare that winner will be contacted via E-mail and needs to claim prize within 7 days in order to receive it. By doing so, you'll eliminate problem of people giving out bogus E-mail addresses in order to avoid receiving advertisements.
2. Open a discussion forum on your site. By only allowing registered users to post, you can collect E-mail addresses and deter pranksters from writing abusive messages at same time. However, if you decide to use this method to build your list, be very careful. Sending advertisements too frequently to regulars of your forum may cause them to move elsewhere and thus reduce traffic to your site.