Nothing to do with Chiltern - but most of the posts aren't anyway
Travelling on a very busy, but not overcrowded, TPE to Manchester the other day an announcement was made leaving Dore that the trolley would not be coming down the train and anyone wanting refreshments should go to the front of the train where the trolley was.
I was in the front carriage and not one person came through. However, after about 15/20 mins the trolley attendant (presumably fed up with the lack of custom) took a walk through the carriage, checked out the second carriage and then returned and started a trolley service. In the standard half of the first carriage at least 6 people bought something, but clearly none of them was willing to walk a few yards forward after the original announcement.
I assume more refreshments were sold further down the train, yet a less proactive attendant would have sold precisely nothing on the journey.