I submitted online and after a few months, a "recruiter" contacted me via e-mail to schedule a phone interview with the hiring manager. It was scheduled and the morning of, he e-mailed to tell me it needed to be rescheduled for the next day at a particular time. I agreed and was available, but the call never came. After waiting 90 minutes, I contacted the recruiter to let him know it didn't happen. He was apologetic and said he'd find out what happened and reschedule. After a week of waiting, I contacted him again and never received a response. The whole experience was very unprofessional from the start. Working with people who don't exercise common courtesy is quite undesirable, so I'm not disappointed it didn't come to anything. Incidentally, I was not a Groupon user at the time, but I signed up to try out the mobile app and the service. On Android, the app was awful and when I tried to use it for my deal at dinner, it just displayed a white screen. The waiter took my word for it and gave me the deal anyway.