The Groupon Deal of the Day is $50 worth of services for $25. They have all sorts of facials, waxing, hair, hair treatments, mani/pedi etc. Redeemable at both the Royal Oak and Ann Arbor locations.
They also still have their $50 for $25 at Nordstrom's Rack as a side deal. Also worth checking out.
http://www.groupon.com/detroit/http://www.groupon.com/r/uu1208530 (if you need to sign up. And yes I do get a referral bonus)