I personally don’t recommend this shop, massage is just okay at best for the most part or as long as it lasts, didn’t quite get the entire hour and felt rushed, expect upsell.
I would be hesitant to whip out a Groupon trying to get a few bucks off. At any sort of business, they are a pain in the ass and it appears that most of the front line employees have no clue that they are participating in a Groupon much less how to redeem them appropriately. Add additional annoyance factor when that employee has a minimum grasp of English.
Reading reviews from Yelp of massage places and the primary complaint of lady customers is "they wouldn't honor the Groupon I purchased". That, and wondering why their $5 tip gets them yelled at by the provider. lol.
There is one place that has a sign at the front desk saying standard tip is $10 to $15 for massage. They are $50 for an hour. Apparently some cheapskates don’t know standard tip for salon/spa services is 20 to 30 percent.