Zestcash offers small, short-term loans that it says are less costly and more convenient than those offered by traditional "payday" lenders, so called because their loans must often be paid back on the borrower's next payday.

Co-founded in 2009 by former Google CIO Douglas Merrill and former Capital One Chief Customer Officer Shawn Budde, Zestcash lends money to customers in Utah, Idaho, South Dakota and Missouri, and plans to expand to four other states in the first quarter next year.

"We're right on the edge of a massive growth spurt," said Merrill, the company's CEO. He declined to disclose the new states but said they represent a larger potential customer base than the existing states.

Payday loans are usually sought by people who have bad credit and little or no cash reserves, to deal with emergency expenses such as health issues or car repairs.

Unlike companies that provide conventional, long-term loans for needs such as buying a home, payday lenders usually don't turn to credit bureaus to qualify their applicants. Most applicants have short, checkered credit histories, so payday lenders assume many clients will default and build those costs into their fees.