As a manager, it's been a personally eye-opening experience seeing how companies pay staff and how the constraints a manager has to work under affects their pay rise decisions. People wishfully hope that they get paid based on their contribution/skill level, but there are so many additional factors that come into play.

In all the technical teams (sysadmins, dbas etc) that I've managed, I've consistently seen variations of between $50k-100k between the lowest and highest paid person of the same skill (ie I'm not comparing junior to senior staff).

The things I learned as a manager:

* Always know what the market is paying for your skills. Even if you are not looking for another job, remain subscribed to job websites so you understand what the market is after and what it is paying

* Sharing salary information with people you trust is incredibly valuable - you need to know where you stand. It's in the companies best interests to keep everyone in the dark - it means you won't know your true worth.

* If you love your job, by all means stay - but make sure you aren't using that as an excuse to cover up the fact that you are scared to make a jump, or that your ego is wrapped up in your job title. There are no medals for long service - and as companies (in my experience) generally only pay market rates to external hires, you are better jumping jobs every few years than staying in the one place. You'll develop more skills, earn more money, and I believe in the long term more employable.