It could be 50% to Groupon or it could be 70%. They take the money straight away, give 33% after 5 days, another 33% after 10 days and the balance 30 days later.
What if loads of your existing custies bought this deal?
Best time to go with Grouipon is if you are about to go bust. Schedule the custies for 3 weeks time, take 66% of the take and go bust having done no cleans.