Part of driving engagement with a service can be the reassurance that people have used it before you. Currently, you can display sold out days, and have them marked as sold out, but you cannot show sold out timeslots.

If you were to introduce sold out timeslots as a feature, it would help us display to the public how much demand there is, and in turn create both a reassurance that other people are booking the event, and also develop a slight 'fear of missing out' effect.

I believe this would greatly help drive uptake of events.