Online coupon site Groupon, after a series of losses and missteps, said that it is replacing CEO Andrew Mason. But the fired chief took it well, even joking about it to employees.

In an email to his staff that was made public Mason joked that he decided that he'd like to spend more time with his family. "Just kidding - I was fired today," he said.

He added that he was "OK with having failed at this part of the journey." "If Groupon was Battletoads, it would be like I made it all the way to the Terra Tubes without dying on my first ever play through," the email said.

Executive Chairman Eric Lefkofsky and Vice Chairman Ted Leonsis have been appointed to the newly created Office of the Chief Executive, effective immediately, replacing Mason, the company said in a statement.

Lefkofsky and Leonsis will serve in this role on an interim basis while the board searches for a new CEO.

Groupon shares plunged 24 percent to $4.53 Thursday in New York after it said that first-quarter revenue will be just $560 million to $610 million, less than analyst forecasts of $647 million. The fourth-quarter net loss widened to $81.1 million. In all, the company has had losses of $724 million over the past three years.

Demand for online discounts has waned as competitors flooded the market and merchants have complained that the coupons disrupt their businesses. Mason tried to lessen the company's reliance on coupons, but the firm's first year as a public company has been a disaster with the shares down three-quarters from the IPO price of $20.50.