The idea began percolating, said Dan Price, the founder of Gravity Payments, after he read an article on happiness. It showed that, for people who earn less than about $US70,000 ($92,105), extra money makes a big difference in their lives.

His idea bubbled into reality on Monday afternoon, when Price surprised his 120-person staff by announcing that he planned over the next three years to raise the salary of even the lowest-paid clerk, customer service representative and salesman to a minimum of $US70,000.

Gravity Payments founder, Dan Price.

"Is anyone else freaking out right now?" Price asked after the clapping and whooping died down into a few moments of stunned silence. "I'm kind of freaking out."

If it's a publicity stunt, it's costly one. Price, who started the Seattle-based credit-card payment processing firm in 2004 at the age of 19, said he would pay for the wage increases by cutting his own salary from nearly $US1 million ($1.315 million) to $US70,000 and using 75 to 80 per cent of the company's anticipated $US2.2 million ($2.894 million) in profit this year.