I was enough challenges to make 40% off for about 3 months now but decided to take a couple months off. It's awesome to get that huge 40% discount, though! I'd buy like 20 kits at once but the savings would be HUGE! Just think, if buy $100 in products, you'll only be paying $60 for them! That's awesome and a great motivation for me!!!! Stock-up time!!!!
I know I'm going to wish I did the challenges in a couple weeks, I'll miss my shopping spree! But I have a lot of baby stuff to buy, and then next month I'll be too tired to do the challenges cuz I'll have a newborn and my son's 4th birthday stuff.
It is a lot of work to get many of them done, but remember you can miss quite a few and still get enough for a discount.
Good luck!