There is no right answer.
As it happens I have already written about this issue for a side project I've been working on to define the best elements of ride design. Here is what I wrote on the matter:
Queue Line Distractions
A Queue Line Distraction is anything which is present in a queue line which in some way prevents the user to be queuing normally. These can include:
□ Seating
□ Vending Machines
□ Kiosks
□ Toilets
□ Queue Line Activities
These facilities pose an issue to normal queuing
When confronted by a distraction there are three ways around the situation:
1) Sacrifice the distracted persons place in the queue by allowing others to go ahead of them
2) Hold the queue up behind the distracted person.
3) Allow others to go ahead but let the distracted person queue cut to the place they were before.
None of these options are ideal.
- The first option is normally considered to be the correct course of action by other guests. You have decided to be distracted and therefore forfeit your place in the queue. However from the point of view of the park this is not a profitable attitude to take as it may detract the guest from being distracted and in the case of a vending machine or kiosk result in lost sales.
- The second option seems harmless but can be very frustrating for those who are left waiting. Queuing is always less noticeable when the queue is moving at a good rate. Even worse is if the shop has been placed too close to the rides entrance there is a chance that a long delay could stop people reaching the station.
- The third option only benefits the person in question while causing confusion and annoyance to everyone else. This option also violates the rules on queue jumping and can result in being removed from the queue.
I've gone onto write about ways to avoid these situations all together but it's all very rough at the moment and way too long for me to repost here.