Definitely worth re-reading if you do any kind of technical support for your job.
I find that most support requests are actually feature requests disguised as an issue. Users will do anything to try and get what they want, and if you allow them too much leeway, you’ll spend your entire working hours running in circles trying to appease everyone. Your patience and motivation will drop, and the product will suffer, because instead of fixing actual problems and implementing new and useful features (that affect everyone), you’ll be re-creating the wheel and diffusing minor issues that only affect a couple people.
Remember – you’re selling a product, and support is more of a democracy, meaning if enough users are complaining of the same thing, change can happen. But if only one person wants something changed, that doesn’t mean you stop everything for that one person because everyone believes their problem is of the utmost importance.
Learn to distinguish between actual support issues and feature requests – you will make your life a lot easier.