Target is gradually expanding a free loyalty program that helps it gather key information about customers’ shopping habits.

The program, Target Circle, started last April in Dallas. Target Circle has steadily gained members and sales, so the company announced on Tuesday that it’s rolling out to five more cities.

Expanding Target Circle members gives the company data on about the 75% of its customers who don’t shop with the store’s credit card that offers 5% back off all purchases. Target can then use that information to email tailored deals and promotions to customers.

For example, if Target knows a shopper frequently buys diapers and products for her baby, Target could email the customer an offer for diapers. Target can also offer customers deals on their birthdays.

Target Circle will now be available in Charlotte, Denver, Indianapolis, Kansas City and Phoenix.

No word yet on when it will be available here in Utah.