It’s the summer of mobile commerce at e-retailer Gilt Groupe. Every Saturday at noon Eastern time from June 22 through August 24, Gilt will offer four “Summer Must Haves” flash sales exclusive to customers using the merchant’s m-commerce web site, iPhone app, Android smartphone app and iPad tablet app.

40% of total revenue at Gilt Groupe comes from mobile commerce, the company reports. Gilt Groupe is No. 13 in the Internet Retailer Mobile 400.

Gilt is promoting the mobile exclusives on its e-commerce site, in its e-mails and in push notifications through its apps.

The mobile-only sales will include one for each of Gilt’s primary categories: Men, Women, Kids and Home. On June 22, the sale for Men will be shoes under $50, the sale for Women will be weekend wear, the sale for Kids will be 25 girls’ dresses for $25, and the sale for Home will be Missoni Beach towels.

“Our members are using multiple devices to shop online, so we want to ensure they’re getting the best shopping experience possible, regardless if they’re on a desktop, phone or tablet,” says Jason John, vice president of online, mobile and social marketing. “At the same time, we also want to offer users new and unique ways to shop, and by offering mobile-only sales and previews that aren’t otherwise on our web site, we’re able to create an additional level of excitement that also gives members another reason to come back every day. Our members have told us this is a feature that they love and we see the results as our mobile customers return at a very high rate.”

Like many retailers in mobile, Gilt registers higher mobile traffic on weekends. And Gilt is aiming these Saturday sales squarely at consumers who are on the go in the summer.

“On-the-go shoppers are taking advantage of summer by traveling more and being indoors less, so to complement their lifestyle, we’re launching the summer sales on mobile,” John says. “Whether you’re on the beach or on a train, you can literally take Gilt with you and shop from wherever you are. These exciting sales will also feature bigger discounts and great brands. For instance, be on the lookout for our favorite summer dresses under $50.”