“After four and a half intense and wonderful years as CEO of Groupon, I’ve decided that I’d like to spend more time with my family. Just kidding—I was fired today. If you’re wondering why…you haven’t been paying attention. From controversial metrics in our S1 [a securities filing] to our material weakness to two quarters of missing our own expectations and a stock price that’s hovering around one quarter of our listing price, the events of the last year and a half speak for themselves. As CEO, I am accountable.”

Bravo, Mr Mason. Schumpeter salutes you for your honesty, your sense of humour and your desire to “give Groupon a relief valve from the public noise” surrounding your leadership of the company. The only snag is that Groupon is unlikely to get much of a break while it hunts for a new chief executive. (In the interim, it will be run by Eric Lefkofsky and Ted Leonsis, two of its board directors.)

The online-coupon business has become ferociously competitive and people are becoming more picky when it comes to choosing from among the vast number of deals for spa treatments, haircuts and other things that are now available on the internet. The day before Mr Mason’s defenestration, Groupon revealed that it had made an operating loss in its latest financial quarter and its shares fell to $4.44 each in after-hours trading. The firm’s market capitalisation has plummeted from around $13 billion at its flotation in 2011 to around $3 billion today.

Groupon did create a new market, but it now faces plenty of copycats such as LivingSocial and has seen behemoths such as Google wade into the business too. Known for “exploding” offers that expired after a short period of time, the firm has been shifting steadily towards deals that stay valid for longer. And it has been building a new business line called Groupon Goods, which sells things such as watches and nail polish at discounted prices.

Diversifying revenue streams makes sense. But in choosing to sell discounted goods, Groupon has plunged into another area that is intensely competitive. The company has also allowed its costs to balloon, particularly in its international operations. It will need to slash these without damaging growth, which will require a tricky balancing act. The firm’s international revenues fell 16% in its latest quarter.

In his farewell missive, Mr Mason said his departure would give Groupon “some breathing room to break bad habits”. Perhaps it will, but curing them will not solve Groupon's biggest problem, which is that the underlying economics of its business model have always appeared shaky. The firm's share price may rise in coming weeks on hopes that a new leader can turn it around, but in the long term its stock is unlikely to be a good deal.