Personalization is having a major impact on Sears Holdings Corp.’s revenue, both online and in stores, the company says. The retailer’s Shop Your Way membership program, which offers customized product offers based on customers’ shopping behavior and other attributes, accounted for more than half of the revenue generated at the company’s Sears and Kmart operations in the United States during the fourth quarter 2012, as well as for all of last year, says Imran Jooma, corporate executive vice president and president of online, marketing, pricing and financial services.

“Personalization is at the heart of what we’re doing,” Jooma says “It’s all about building customer relationships.”

In the Shop Your Way program, Sears, No. 8 in the Internet Retailer Top 500 Guide is creating new ways for members to interact with Sears and Kmart. Kmart, for example, last week launched special Shop Your Way sites for fans of musicians Nicki Minaj and Adam Levine at ShopYourWay.com/Nicki and ShopYourWay.com/Adam. The sites let members comment on apparel designs Minaj and Levine are working on and enable shoppers to sign up for  alerts when the designs are available for sale through Kmart stores or Kmart.com.

ShopYourWay members can also log onto ShopYourWay.com to click into a coupon section for tailored offers based on their past purchases, and check a message center to see all the customized marketing e-mails that Sears and Kmart brands have sent them without having to search through their personal e-mail inbox.

Although Sears doesn’t break out its web sales, its personalization efforts contributed heavily to a 25% boost in web sales for the fourth quarter ended Dec. 31 and a 17% increase for all of 2012, Jooma says.

The company is also expanding personalization in other ways designed to build relationships with customers, whether or not they’re members of the ShopYourWay program, Jooma says. For example, when Hurricane Sandy hit the East Coast last year, Sears sent customized offers to customers in hard-hit areas in New Jersey and New York based on information such as their ZIP code and past shopping behavior. In fact, the retailer has developed a storm-tracking center that monitors weather patterns throughout the U.S. and sends personalized messages to customers to warn them about coming storms and alert them to special offers on items like snow shovels and power generators.