I guess I can answer this, I've got 21 years in at one of the OGs of SV. When I came on board all the old timers told me to get everything I wanted up front so I beat them up pretty hard (they really wanted to hire me). I did fine but that was pretty much it aside from 1-3% raises every year and often no raises at all. Since we are a very flat company there's not a lot of room for a promotion -lots of chances to do other things but not a change in pay bands unless you go from tech to sales. It took six years from the time I started actively pursuing a promotion until I finally got one -this included two job changes and 8 managers. The promotion was a bigger deal than I thought because not only did I finally get a decent raise but it moved me into a managers level for bonuses and stock options and that equates to a 20-30% increase.
Even if I didn't get promoted the money was fine, I have 6 weeks defined of vacation, good benefits and I've worked from home since 2003 -a lot of which I'd lose if I went to another company. Several years back I tried to assign a monetary number to what it would take to leave and it was between 25-30K which I might be able to get but you just don't know what kind of rats nest I'd be walking into, at least here I know what I'm dealing with.
I was like most people in IT when I started here, I had done a lot of job hopping, made good money and was a temporary millionaire at some bullshit startup. What I didn't expect was to stick around. When I started half the team had been at the company for over 20 years and I thought that they had to be nuts -a few people never worked for any other company 45+ years of service. Then one day I realized I had been here for a decade and then 20 years and now I have 9 years left before I'm sitting on a beach drinking Imperial and being bitten by mosquitos so I figure if I can do it here I might as well.