Groupon users, choose sides.

Earlier this week, law firm Edelson McGuire filed a class action lawsuit against Groupon, a Chicago-based company that offers daily discounts online to local businesses. The lawsuit accuses Groupon of violating gift certificate laws by including expiration dates on the discounts.



Groupon CEO and founder Andrew Mason responded to the lawsuit on his blog, saying he would fight fire with fire.



"In fact, we've decided that the best way to respond is by organizing our own class action,” he wrote. “If there actually are customers out there that feel like we've let them down, we want to get them their money as quickly as possible. Join our class action here."



Groupon, which launched in October 2008, has 2.6 million subscribers in 38 cities. The company’s rapid growth has spawned a slew of rivals. Last month, Groupon filed a lawsuit in Florida accusing another company of trademark infringement.



The class-action suit filed by Edelson McGuire on Tuesday states, "Groupon employs a business model where consumers are enticed to purchase a gift certificate, and after the consumer agrees to purchase the certificate, Groupon imposes post-contractual terms on the consumer containing illegal expiration dates.”



The suit says Groupon “expressly advertises itself as a company that does not impose, in its own words, 'gotchas,' on the consumer. In clear violation of the law, Groupon imposes illegal terms or 'gotchas,' post-agreement, on the very consumers it prides itself on helping.”



(Read the full lawsuit against Groupon here).

Groupon’s Mason responded to the lawsuit on the company's blog, GrouBlogpon.com.

"As a company with one of the most irrationally liberal customer satisfaction policies on the planet (we refund anyone that feels like Groupon let them down for any reason) we're baffled by this whole thing," Mason wrote.

(To read Groupon's "irrationally liberal customer satisfaction" policy, check out Mason's Feb. 2, 2010 blog post, which explains "The Groupon promise.")

In his blog, Mason took shots at the Edelson McGuire lawsuit.

"We can think of two possible explanations for this lawsuit,” Mason wrote.“1. The law firm sees an opportunity to exploit our success and make a bunch of money.“2. We are indeed systematically deceiving our customers, but instead of taking advantage of our 100 percent open refund policy or telling us about their problems or sharing them in a public forum, our customers are secretly gossiping about them to each other and Edelson McGuire, kind of like Emily Johnson did against me in 9th grade (Emily if you are reading this I want my cabbage patch doll back)."So Groupon users, you have options. Which class-action will you join? Take the Tribune poll