Earlier quoted context omitted.
Why do you care what the profit margin is? Either the product or service is worth more to you than the money that they're charging, or it isn't.
>>Why do you care what the profit margin is? Because not knowing it creates an information asymmetry and makes it more difficult to make a rational decision about whether to pay for the product or service, or look/wait for alternatives. It's not just about what the product or service is worth to me. It's also about a sense of fairness. I'm OK with a 20% markup on bottles of water at ball games. I'm not OK with a 200%…
It makes sense to compare a product offering with other offerings on the market, but it doesn't make sense to me to care about the profit margin. What if one firm can offer a product cheaper than all equivalent competing products, but with a much higher profit margin?