How did Chrome become so popular instead of Firefox in the first place? Was it purely Google's advertising of their browser? Brand recognition is so important to typical consumers.
Disclosure: Happy Firefox user since v1. Sometimes I was jealous of Chrome's speed, sometimes I was weary of Firefox's memory leaks, but never enough to leave the flexibility and customizability the Firefox provided.
EDIT: ... and now Firefox is fast enough, and isn't a memory hog anymore, so I continue to be a very happy Firefox user.
Edit: Saw your edit. Glad the firefox memory problem was resolved.
Chrome was based on Safari and was far far faster than anything else available on Windows at the time. Not only that but they moved fast and kept improving.
Firefox is great now but it took a long time to catch up.