Putting a link on your site is another way. There are pitfalls. First, mailboxes are overloaded. Seven percent of users claim to receive 200 or more. Your e-mail will break through the clutter only if it is welcome and succinct.
Customer service is another issue.
Finally, you have to avoid the appearance of Spamming. There are three tests you can apply to find out. In fact, of all the commercial categories in the survey, travel was tops. Because air travel prices fluctuate dramatically, based on availability of seats. Books may be an ideal product for e-commerce, but their prices are more static and availability is not as much of a problem.