Of course profit is ultimately the metric that counts.
But time and time again in the tech world we've seen that it's much easier to build something cheap and ubiquitous and eat your way up the value chain than it is to start at the top and try to tenaciously cling there. It didn't work for Apple last time and I think it's starting to slip for them again now.
What makes you include GMail in that list? It has, by all measures, failed to move up the value chain, its revenue is completely eclipsed by that of Exchange. (Disclaimer: I work at MS.)
My question in response would be: what accounts has Microsoft lost to Gmail in the past couple of years?
From my connections, I'm aware that much of the startup world is on some mix of Gmail for Domains, Google Apps, and/or Mac for desktops/laptops. Microsoft really doesn't play.
Granted, those are small accounts, but I've also seen some household name established businesses ditch Exchange for Gmail. And in a world for which changing enterprise platforms almost universally elicits dread, the announcements were met with cheers. Really loud cheers.
And to answer in part: again, read Christensen. It's not that the cheap competition generates more revenue (though in some cases it does). By that metric you're making the same strategic error as recoiledsnake. It's that by growing marketshare, disruptive innovations suck the revnue out of the market.
It's what Red Hat did to Sun. It's what Craigslist did to classified advertising.
But time and time again in the tech world we've seen that it's much easier to build something cheap and ubiquitous and eat your way up the value chain than it is to start at the top and try to tenaciously cling there. It didn't work for Apple last time and I think it's starting to slip for them again now.