Re: Correct, but money rules...
I'm pretty sure WIndows 10 will fail spectacularly.
Windows 7 users have no reason to "upgrade". There is nothing tempting about Windows 10 for them.
Only Windows 8 users have a real reason to "upgrade", but Windows 8 doesn't have a large market share. Windows 10 GUI changes should really have been a service pack for 8, as an apology for its clumsy GUI.
PC sales are down, and probably mostly bouyed by corporate sales. Corporations have only just transitioned to Windows 7, if that. No way will they transition to Windows 10 as it looks at the moment.
MS tries to charge you for an OS that is essentially a tool for MS to monetise you. Not a good plan.
The "free" version of Windows 10 is essentially a conversion of another OS (Windows 7 or 8) into an operating system where control of it has been transferred to MS (via the mandatory update path).
The new version you get is tied to the hardware. It is unclear what happens when the motherboard dies, or the harddisk needs upgrading, etc. If you previously had a fully payed for version of Windows,
with installation media, installable on the PC of your choice, you would be MAD to swap that with a Windows 10 version! (I can see lot's of back pedaling by MS in the future when angry hordes have finally discovered what they accidentally have agreed upon.)