What is Variable Pricing?

What the heck is variable  pricing? It works like this: At 12:01 A.M on the day a new book goes
live on our  site, it’s offered free. Yes, you read correctly. The first copy is FREE! With  each download the book rises in price by twenty five cents until it reaches its  full retail price or 24 hours have passed. At that time, the book goes to full  retail price. Coupons and discount codes are not applicable for
any book that is  under variable pricing until it reaches full retail price.
Come early on release  day to save:  September 1st.