I tried to apply to Groupon online multiple times. One of my friends knew a recruiter and only after he forwarded my resume did I hear from them. First was an initial phone call - tell me about yourself, walk me through your resume, why sales - and then a second phone call with the same questions but different recruiter.
They asked basic questions, although with percentage math questions and how Groupon could benefit small businesses. Third phone call was a role play scenario, where I pretended to be a Groupon rep and talk to a merchant. What they want to see is how you sell the company and what Groupon can offer, and when they try to get off the phone, be persistent and confident.
Lastly, I interviewed in the office with 3 employees, and since the VP was out of the office, he gave me a call the following week. I was then offered the job, but declined due to timing. It's a great company to work for, but my one piece of advice: make sure you want to be in sales! Oddly enough, I realized sales wasn't for me by the end, but I still love Groupon for what they do.