No matter how often you test the performance of your site, we all know that sometimes, outages or other errors are inevitable. That said, we’re always on the lookout for unique, innovative or informative error messages.

Here’s one we came across today, implemented by the “deal of the day” company, Groupon. Groupon launched its first nationwide deal today, $25 for $50 worth of merchandise at Gap, and was quickly overwhelmed by the response. TechCrunch reported that “as of 11 a.m. PST (the e-mail blast went out at roughly 6 a.m. in each time zone), Groupon has sold 200,000 Groupons and is currently selling roughly 10 per second.”

The result has been inconsistent availability and shaky performance. But kudos to Groupon for keeping their customers informed. And for offering to contact them when the site was back up and running.

Here’s the message we got when we tried to visit the site this morning.

As these type of sites gain popularity, providers will need to take extra steps to ensure their websites can hold up to the big deals of the day.