"We do quite a bit of testing, and this is one of those little things that makes a big difference to the bottom line," said Leuenberger. "It will boost the average order value."

In fact, the site is getting a facelift this year. This year's new features include an option for shoppers to sign up to receive the best offers from e-tailers via e-mail every Monday; RSS feeds that provide up-to-the-minute updates on deals, discounts and promotions; dedicated pages highlighting merchants with free shipping offers, gift cards, and a holiday-themed page; a home page featuring hot holiday products and category-specific pages for quick shopping and product search capabilities allowing shoppers to search more than 15,000,000 product SKUs. To get information on how to get listed at the site, contact Kristyn Golier, vice president of merchant development at Mall Networks, the company that operates the site, at 781-541-6819 or kgolier@mallnetworks.com.

"There are two things to keep in mind," he said. "One is that sometimes 'Tell A Friend' doesn't work on its own. You need to say, 'tell a friend, and get x amount off the next purchase.' Again, some may balk at offering yet another discount, but in the end, you get two people buying instead of one, so you can still profit. "The second thing is that the thank-you or confirmation page is the most viewed by customers, naturally, you have their attention because they want that assurance, and to know what's going to happen next with the order. It's a great idea to take advantage of that, and offer incentives for them to tell their friends about your products."