Ease of use, flexibility in terms of what can be logged by user (eg. I like that you're able to log things such as 'food not eaten' or even just simply logging when people have used their bins), how well all devices are connected together so if one goes down then everything else does too - this means no more manual data entry! Not much really apart from ease of using system but maybe some training would help with getting everyone up to speed quickly? Would also benefit greatly for organisations who want something simple yet reliable which they don't need constant service support. We've been tracking our weekly usage stats since April 2017 without any issues despite many other systems going out before ours did.