Two fitness experts have developed a remarkable exercise system that appears to yield immediate and prolonged improvements to a person's physical and mental health. In careful testing, they have found that the system is accessible to people of different ages and fitness levels. Furthermore, since the system involves unusual techniques, custom pieces of small equipment, and natural dietary supplements, the system would take years for competitors to replicate. And when they tested the system during a two-month trial, potential customers stated emphatically that they would pay the stated prices to continue in the system and that they preferred it over other forms of exercise. All evidence indicates that the new exercise system will have successful launch in the market.

Which of the following would it be most useful to determine in order to evaluate the argument?