How can Groupon offer such inexpensive IPL Photofacials? Do they work? Scam?

I can't speak to other practices, but cost will vary due to skills, expertise and technique. I usually recommend a combination of treatments with IPL for best results. I suggest adding microneedling/prp to improve skin quality and tone. See an expert. Best, Dr. Emer

They're likely using Groupon as many spas do to get business and foot traffic. Also good reviews come out of Groupon which helps businesses. It is a win win situation. Just call and ask what kind of IPL, who is firing the machine and how many sessions. 

My personal opinion on groupon is that any reputable physician would not cheapen their practice by offering one. In my area, the places offering groupons are the ones not doing well and trying a last ditch effort to grab new clients. With groupon, the businesses offering them lose money on each person who comes in with one, but they are hoping to upsell that person to do other things. Often the person performing the service has no idea what they are doing. You get what you pay for. With IPL in particular, the risks are high, and the worst case scenario is you get one for cheap and end up with burns on your face.