Its hard to say. Bu where Chrome made the most impact is probably not the geeky community, but mr everybody.
And how?
=> link on google.com telling you have to get Chrome
=> bundling+force install+defaulting Chrome when updating acrobat reader, flash, etc, even from Firefox or IE.
Both work fine as long as Chrome is a decent browser (and Chrome is a very decent browser that's for sure)
They stopped the later and still do the former (it doesn't necessarily show up in all situations so your mileage will certainly vary), any time you go on Google.com with any browser. At least the former is not morally wrong, but it certainly has a huge impact due to their near monopoly on search, and people believing that Google is the Internet and if Google says something, they should probably do it.
I don't think Mozilla could beat neither of those 2 points, even thus they could have lowered the overall impact by doing things better (especially their switch to 6 weeks release without having silent update/auto addon compat, that one was just plain dumb).