Understand the system your customers are using when they contact you with problems - remove the headaches of asking them to describe their set up and get right to the point of helping them.
Understand what systems your customers prefer to use. Is that customer always accessing your site via their Phone? Do they prefer desktop? Use this information to analyse individual customers or your entire customer-base.
Analyse your error logs to get a comprehensive picture of the scenario which created the error. Don't guess any more - here's a tool to help you understand the situation more.
You'll know what kind of system your customer is using; and be able to change the content accordingly.
Is that request from a real user or a crawler?
Let us know! We'd love to include it here (or even feature you in a case study!)