I had been purchasing Humann products for over 3 years. Recently, I got a mail flyer with a sale of by 2 get two free. When I attempted to check out, the code was not recognized. So, I finally phone in an order and the rep. Tried to charge me more than was stated in the flyer. The stuff is expensive enough without having more added to it. A very poor constructed web site and poor customer service. I am going to be looking for other similar products.