If I had to speculate, it seems like the restaurant was likely faltering already, and the owner tried to attract new customers with some Groupon deals. It didn't end up generating the kind of revenue he had hoped, it didn't result in new returning customers, and the restaurant closed down. I think if you have a restaurant that is really great and you want to the word out, Groupon can be a real driving force in getting people in the door. However, if you cannot guarantee the kind of experience that is going to make them come back, and/or you are already walking a tight line financially, it might not be a good idea at all.