Dunkin' (NASDAQ:DNKN) wants consumers to both sign up for and use its DD Perks rewards, and it's willing to incentivize them to do so. The chain will give members of the program a free doughnut every Friday in March with the purchase of any beverage.

"We're always looking for new ways to show our appreciation to Dunkin' fans and our DD Perks Rewards Program allows us to celebrate them with fun and exclusive offers throughout the year," Dunkin' Vice President Stephanie Meltzer-Paul said in a press release.

The exterior of a Dunkin'.

Dunkin' plans to give loyalty program members a free doughnut every Friday. Image source: Dunkin'.

Dunkin' wants to grow digital

DD Perks already has more than 13 million members. The chain wants more people to join because the program drives sales and allows it to market to members for free.

For example, Dunkin' can send an afternoon deal to a customer who regularly visits in the morning. It can also offer broader deals to lapsed customers and drive spending by promoting limited-time offers.

Starbucks, a chief Dunkin' rival, has led the way in using its app-based loyalty program in these ways. Dunkin' has been more than willing to learn lessons from its rival and has unabashedly copied ideas that have worked.

Free isn't quite free

In exchange for your free doughnut, you are giving Dunkin' access to your personal data. The chain will be able to track the purchases you make, since to get the free doughnut and similar rewards through the loyalty program, you need to have your app or card scanned. For many, especially people who are already members, that's a small price to pay for a month of free doughnuts.

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