The other Japanese text reads (my rough translation, you get what you pay for):
To our customers who ordered Bird Cafe [n.b. name of advertiser]'s "Kinsei Osechi" [n.b. name of product -- osechi is a a food box delivered at New Years], related parties, and Groupon's fans: we are sorry for having caused you trouble with the Kinsei Osechi Groupon offer. Our CEO Andrew Mason, founder of Groupon, explains how Groupon will take the utmost measures to stop similar incidents worldwide in his apology message:
Video goes here.
Not only Groupon Japan but all worldwide Groupon companies will take corrective steps to prevent this sort of occurrence from happening again. The measures include:
+ Strengthening pre-deal investigation of merchants
+ Improving the setting of deal size limits [to prevent overwhelming merchants' ability to deliver]
+ Establishing a dedicated customer support office for purchasers of Groupons
+ Improving training of employees and our internal management systems so that our customers and merchants can trust us sufficiently to do business.
Thank you for using Groupon. We hope to continue earning your trust in the future.
[Transcript of video begins here. You can listen to English.]
As for apologizing to the merchants, I am assuming that they must have known all the way along about how many orders were they capable of handling before they had to resort to delivering that what was not the same as the advertised deal.
I think that assumption is perhaps optimistic. Your average local takeout place is not Toyota: they probably run things mostly on feel, rather than on having a rigorously documented and optimized process, and it is highly unlikely they've ever thought through capacity planning for "Can you take five times your busiest day ever? Can you take ten times your busiest day ever?", because for traditional businesses that just doesn't happen. Groupon's strategy for addressing this apparently includes communicating to merchants that Groupon is capable of overwhelming them past anything they have previously experienced.