Almost every Internet user who initiates contact with your e-commerce site is a potential paying customer. Sometimes all it takes to turn browsers into buyers and one-time customers into repeats is a few gently persistent and subtly persuasive reminders that your site is still there.
Perhaps a site visitor filled out an online form requesting a brochure, catalog or information. Instead of passively waiting for the recipient to initiate a sale after they've received your material, you should contact them instead. Wait a week or two after you've mailed the info and then send a follow-up e-mail to the prospective customer. If you include some type of limited time offer, the follow up could result in an immediate purchase.
One-timers can become repeats if you maintain contact with them. Send special offers commemorating the anniversary of their first purchase. Or notify them when something they previously ordered goes on sale or is about to be discontinued. If a customer buys a consumable product, e-mail them when you expect their supply to be completed.
If you've organized the collected e-mail addresses from browsers and buyers into a comprehensive database, you should be able to disseminate information rather quickly. When inputting the data, immediately set up a corresponding reminder alert for a realistic time when you can make the next contact.