This attitude works out if your extremely good in your Spezialisation. I had kept track of my own ROI for the companies I worked for, granted them a bit of that

This attitude works out if your extremely good in your Spezialisation. I had kept track of my own ROI for the companies I worked for, granted them a bit of that and the rest should be for me. It worked because I always had the digits at hand. Basically "I need a raise, I have 3 jobs offers lined up, your making this of me and I demand x% of that otherwise you loose y over the course of z. Deal?"