CHICAGO The Chicago-based Web site Groupon, which operates in 28 markets and offers daily discounts on everything from language classes to spa services, hosted its first customer-appreciation party at Carnivale on Thursday night. The event also celebrated the site's 14-month anniversary.

"Groupon's calendar has 12 35-day months," explained vice president of marketing Mark Desky, "but we've been operating for 14 traditional  30-month days. So we had fun with that." According to Desky, billing the event as a 14-month anniversary party was a reflection of the brand's irreverant style. "We have humor writers who work on the copy for our daily emails," he said, "and we wanted to infuse our event with that same brand of humor."

Less humorous—for planners, at least—was Thursday night's weather forecast, which predicted 12 inches of snow. (Ultimately, the night was frigid and snowy, but accumulation was less than predicted.) "The biggest question for us was how many people were actually going to show up for the event," even though more than 600 had said they would attend on the site, Desky said.

On the day before the event, organizers sent out a reminder email; only 75 would-be attendees sent regrets, and the bash ultimately drew 650. "Our customers are really enthusiastic about Groupon, and they certainly delivered for our anniversary party," Desky said. "Everyone who came showed up looking for a great time."

In addition to summery menu items such as raspberry mojitos and guacamole and chips, attractions that ranged from strolling magicians to pampering treatments distracted guests from the bleak January weather. Also included: live entertainment from DJ A-Cup, who at one point spliced the Groupon hold music with a track from Lady GaGa. "It wouldn't have been a very Groupon party if it were just food and drinks," Desky said.  "We realy thought through ways to make it more engaging."