The popular Ottawa-based coupon website Kahoot has closed down after two years in operation, leaving businesses and shareholders bewildered.

Over recent weeks one former shareholder has noticed that Kahoot had stopped offering new deals.

Then, suddenly, on Friday an apology appeared on the company's website

"It's been a pleasure serving the Kahoot community for the last couple years," it said, with no further explanation.

"I think we're in the dark, and I don't even know if there was anything fishy happening. I don't even know whether it was operated appropriately," said former shareholder, Stephen Lau, president of Ottawa Kiosk.

"For two weeks, I've tried to get a hold of the owners to find out what happened. They haven't returned my calls or emails, and the address listed on its website is this vacant building under construction," he said.

CBC News tracked the website's address to a Kanata home. But it turned out the owner used to live there, but moved in February.

Hair salon owner Joseph Saikaley said Saturday that he's not surprised.

He said he sold $7,000 worth of coupons last year. But when the coupons were delivered, they were not offering the deal or conditions he had negotiated with Kahoot.

"Disaster, [it was] a disaster, but we tried to make it as pleasant as possible. It wasn't fun for the client as much as it wasn't fun for the service provider. The person in the middle didn't care what happened in between," Saikaley said.

"I think these coupon companies are just taking advantage of businesses that were looking for new business. I think now most businesses are realizing, 'Don't make a deal with the devil, do the deal with the public instead,'" he said.

Lau said he pulled out as a shareholder when Kahoot changed its return policy.

"It's frustrating because the only way we can get action is through legal means and that's all you can do. We feel like our hands are tied."

Several businesses told CBC News they will not be affected by the closing of Kahoot because they were paid up front, and they can continue honouring customers' coupons until they run out.