There are a few advantages, being that both the seller and buyer can see what current market is for their property. The open nature encourages interested buyers to make as attractive an offer as they can knowing other potential buyers are watching, and competing. 

At the same time the system is potentially susceptible to outside influences. Since the offers are non binding (written real estate offers are binding if accepted since they are contracts) there is a potential for outside influence in the form of multiple low or high offers altering the perception of genuine buyers.  As a marketing and exposure tool N-Play could generate property interest and help both buyers and seller better understand the current market price for property.