What if... Windows 8 had been a free update?

During the last days I have been thinking about possible strategies MSFT could have used to boost W8 users number, and that came to my mind:

What if W8 had been offered as a free upgrade for EVERY W7 PC? That way, almost anybody would have upgraded without thinking twice IMO, people are reluctant to pay for W8, but if it was offered at no cost, the would give it a chance (at least for apps like Xbox music). That would have increased the number of W8 users while, at the same time, reducing W7 number (they don't want another XP-style fragmentation). Of course, there would have been several problems:

  • Revenue: MSFT would perceive nothing for W8. Actually, I don't think it is a problem: they would offer 8.1 as a PAID upgrade (20-30$) and upgrading from Vista or earlier would cost the same. It would be easy to convince people to pay for W8.1 (which is a consumer feedback based upgrade, and incremental instead of revolutionary), and there would be a bigger number (while some argue 8 is worse tan 7, I doubt someone thinks W8.1 is worse than 8).
  • OEMS:Sales wouldnt have been boosted by Windows 8 launch, but break-up OEMS (see HP) is already unavoidable.

So, do you think it would have been a good strategy for Microsoft?

Now it is too late, and the only alternative I have thought of is: what if they released W7.X? It would be more or less like WP7.8, introducing existing users the benefits of the new OS, but with the same underlying OS. Giving W7 users the option to run some metro apps(mail, music, skype..) without getting rid of the start menu. Actually I think it would be a waste of resorces, but what is your opinion?