Biopure Corp. is developing a human blood substitute called Hemopure. Unlike like donated human blood that needs to be refrigerated and expires after a short period of time, Hemopure is shelf-stable and can be stored for two years or more. It does not need to be matched to a person's blood type like donated blood does. These factors make it well-suited for trauma cases where blood must be transfused at an accident site or on the battlefield. Which product characteristic influencing the rate of adoption does this represent?