I thought I'd share mine. This was a year ago. The company I worked for was decent, as they treated their employees well, but they didn't know how to manage to save their life. I'm a senior front end software engineer and am intermediate in the back end. I was making $54k, and where I live the average is $75-116k JUST for a senior front end developer with no back end experience.
I didn't know what my value was worth until three years later ($54k was my final raise) and I told them I need a $30k raise ASAP. Knowing I wouldn't get this raise, I started looking for a new job. I immediately got multiple offers $20-$30k above what I currently make from multiple employers.
After a week of me telling them what I need, they came back with just $62k. I told them they can match me with $85k (the offer that was pending my acceptance) or I would walk. They couldn't, and I did.
Shortly after I left, they lost a bunch of other engineers because I was their only good front end developer. I'm extremely happy at my new job, and I've worked there for a year, and am getting a raise here soon.
Moral of the story: know your worth and don't accept less.