Speaking only for myself, as a merchant in Chama. The train counts are very useful in inventory control. If you have records going back a few years it allows you to pick up on trends. This gives you a better opportunity to control your inventory. You don't want to much inventory & just as bad would be to little. So anything that helps you make an educated guess is well worth the time it takes to track it.
I also use the daily radio train counts to help me with inventory control & it also helps with when to advertise. If I know I am going to be busy I can use the advertising money for a time when I won't be as busy & hopefully get more bang for the dollars spent.