Ars Technica makes a pretty good case that the sales of Windows 8 are pretty good so far. On a par with Windows 7, in fact – the Wall Street Journal estimated 40 million copies were sold in that first month for Windows 7 too. So everything looks peachy, right?

Not from where I’m sitting. Here’s the problem as far as I see it.

Windows 7 – like Vista – was launched with a special discount: everyone who’d bought a PC in the last 6 months got Vista at a serious reduction – the cost was £12.99 in my case, which is basically the cost of media and shipping and handling. The same discount applies to Windows 8, too.

The difference is that Windows 8 also has an “early bird” discount, too. When it came to Windows 7 or Vista, you paid a lot more without the “recent PC” deal, but there is for Windows 8 – right now I can upgrade for £24.99 (the price on the US site is $39.99).

It doesn’t take a maths wizard to work out that this is only a third of the income for Microsoft. But also it doesn’t take a genius to work out that this discount isn’t making any difference. The people that bought Windows 8 so far are much the same ones that bought Windows 7 last time around.

Of course, it’s too early to tell exactly what the implications of this are, but it represents a real opportunity. For Apple, for Android, and for desktop Linux. For someone like me, who’s spent an entire career developing with Microsoft products? Well, let’s just say I’m not sleeping as well as I used to…