What are the services you want to upsell? I will be offering my current wax clients the groupon deal I am running for nails but directly that way I keep more. I also like to choose a few products to retail and then discount them a bit, that way it is not extra service time and still making some money. I also will offer a discount if they pre-book for their next service that day.
What is the deal you offered for the Groupon now and how many people did you get....I'm considering running one.