Sample sales were once exclusively the bastion of savvy (and determined) New Yorkers, but the markdown events have migrated from the showrooms of the garment district to the simplicity of point, click, and buy. A crop of recently introduced, invitation-only online shopping Web sites such as Gilt Groupe, ideeli, and HauteLook offer designer merchandise at a deep discount: Apparel, accessories, and home goods are sold at prices 30% to 70% below retail for a limited time only (generally between one and three days).

While the appeal to shoppers is obvious, online sales offer a significant benefit to featured brands as well: Namely, designers can clear end-of-season inventory discreetly, eliminating the stigma of merchandise sitting on the floor of an off-price retailer such as T.J. Maxx or Marshalls. Retailers always have excess inventory, and discounting product is inevitable. “The challenge is to do so in a way that reinforces brand identity, quality of products, and value of discounts,” the marketing and communications manager for TheTopSecret .com, Reva McEachern, said. Invitation-only online sales bridge this gap.

There are other benefits as well. The designer of MRE Jewelry, Mallory Eisenstein, recently participated in a sale on HauteLook .com. She said that “access to a new base of consumers” was one of the primary incentives for working with the site.

Ready to shop? Here are the major players in the online sample sale arena, from A to Z:

Editors’ Closet offers an assortment of merchandise from apparel to watches and sunglasses, even luxury pet carriers. With a predominantly European team in-house, the site frequently offers niche, up-and-coming designers. Forthcoming sales include Tom Ford Sunglasses. To join, enter e-mail newyorksun@editorscloset.com in the referral box on the site.

The first online sample sale site to launch, Gilt Groupe went live in November 2007. The site hosts an average of between two and three sales daily covering men’s and women’s apparel, jewelry, children’s wear, and home. Upcoming sales include Costello Tagliapietra and the Vera Wang Lavender Collection. To become a member at Gilt, visit gilt.com/nysun.

Another Web site, ideeli, bills itself as one that offers not only discounts on luxury merchandise, but also access for members to exclusive shopping events and giveaways. The company’s chief executive officer, Paul Hurley, told The New York Sun, “We have created an environment that allows our members to discover the brand and the products — and we’re the only site that does this with editorial, links, and community.”

Ideeli is the only site to offer the option of membership levels; First Row membership is $83 a year and provides exclusive access to giveaways and first dibs on sale merchandise, while Second Row membership is free and by invitation only. Upcoming sales include Christian Lacroix. To join Front Row, go to ideeli.com.

Regent’s Secret offers the most competitive rewards program in the online sales business. By inviting a friend, each member earns 5% of the value of that person’s purchases for the duration of her membership. Upcoming sales will offer designs by Evisu, Taryn Rose, and Chip & Pepper. To sign up for membership at Regent’s Secret, enter the code “secret” for access.

HauteLook.com creates unique content that includes streaming video and images. The site also boasts an online magazine that provides an inside look at the fashion industry, with contributions by top stylists, designers, and editors. “Many brands use HauteLook as not only a means to clear inventory, but a way to market their brand to a customer they may not already be reaching,” the company’s chief executive officer, Adam Bernhard, said. Upcoming sales include Frankie B, Black Halo, and Sass & Bide.

Owned by the same parent company as the discounter Loehmann’s, Ruelala.com offers access to merchandise from the current season. The senior vice president of marketing for the site, Stacy Santo, explained that “unlike online sample sales, Ruelala.com carries a full size range and deep inventory levels.” There is also a generous 30-day return policy — no questions asked. To join, click “invited by a member” and enter the e-mail address vip@ruelala.com.

Recently launched, The Top Secret is a sister site to Top Button, an online shopping guide. According to Ms. McEachern, The Top Secret “is not just about making fabulous purchases at deep discounts, it’s about being the first one in the sale to get the hottest handbag or sunglasses, and then bragging about it to your friends. It’s shopping entertainment.” For more information, go to thetopsecret.com or topbutton.com.

A senior editor at Style.com, Laird Borrelli, offered wisdom for online shoppers: “Determine how much you have to spend before you shop, and try not to get carried away. In the heat of the moment things tend to seem more desirable than they are afterwards.”