Money One offers a Kasasa Cash checking account that pays an annual rate of 3.01 percent on the first $10,000 and 0.51 percent above that. Its Kasasa Tunes account offers monthly reimbursements of up to $10 for digital downloads. The credit union refunds up to $30 in ATM fees each month.

To qualify for the high interest rate or digital rewards, Money One customers must meet requirements similar to those at Patapsco.

It is those requirements that pay for the program.

The debit card use generates revenue because each time the card is used, a merchant pays a fee to the institution for processing the transaction. Smaller institutions can charge a higher fee than big banks. And by requiring customers to use direct deposit and online banking and get statements online, the banks save on costly paperwork.

Customers who do not meet the qualifications forfeit the higher interest rate or reward for that month, but they can earn it the next month if they fulfill the requirements.

Patapsco has offered the rewards program since January. Phillips said it's too early to assess the impact, but "it should help with the growth of the bank."

Money One, which has nearly $107 million in assets, has been offering the rewards for more than a year and has added 1,700 Kasasa accounts, Harvey said. And those customers are doing other business with the credit union, such as refinancing their mortgages, she said.

Both institutions also offer a Kasasa saver program that pays an annual rate of 1.01 percent on a savings account, if the customer meets the Kasasa rewards checking requirements.

A single product or service like Kasasa is not going to reverse the years-long trend of consumers shifting to large banks, said Bankrate's Bell. But an individual institution can benefit from the Kasasa program and so can its customers, he said.

"For customers, it's great," Bell said. "They are going to get these benefits. It's free checking."