Yes. Set up a new coupon under Coupons tab of the "Appointment Types" page and select "Each code can be used: Total number of uses..." and set it as "1". Then with each purchase on the deal site (Groupon, LivingSocial, etc) you'll create a new code to distribute to each customer under "Enter multiple coupon codes...".
Some deal sites (like Groupon) will provide users with a list of potential codes that will be generated when a purchase is made. If you're using one of those deal sites, after receiving the potential codes list each code can be added into the "Coupon Codes" area in Acuity, so that clients can immediately use their deal site generated code on your Acuity scheduling page.