Here's the slide from WMPU:
Read a slide of stats like this and you get an impression of a fast growing mobile OS, though pessimists would also point out that the '8' and '24' markets listed above didn't include some of the biggest countries, like the USA or China. It's clear that Windows Phone does have some way to go still in these important territories and I do believe it can make progress once Windows Phone 8.1 is out across the board and word of mouth spreads about its huge usability improvements.
The iPhone comparison can be taken either way. On the one hand, these 24 markets were probably poorer countries where the iPhone is crazily expensive (even more than in Western markets - cough); on the other, being the established alternative to Android is still a worthwhile position to be in.
Take the 270K apps figure with a pinch of salt, mind you - vast numbers of these are trivial 'wizard-made' App Studio efforts and not serious apps and games from serious developers - you'll notice that AAWP has stopped reporting Store numbers in the last year. In fairness, there's lots of fluff in the iOS and Android app stores too - the real story isn't with absolute numbers anymore and hasn't been for ages.
Other stats included in reports from WPC include 12 million Lumia 520 devices having been activated since launch, rather definitely making it the best selling Windows Phone yet made. I'd be fascinated to know worldwide sales figures for higher end phones though - the Lumia 920, 925 and 1020? Anyone have a data point here?