20% of the general public in Poland, Mexico and some Eastern European countries don't agree with that claim. People forget how varied is the smartphone market across regions.
I can't find anything to back that claim up. The only thing I can find that's even close suggests that Nokia had 19% marketshare in Mexico for 2012, but based on other stats that's by far accounted for by Symbian devices:
People want smartphones. WP phones are the cheapest entry level smart phones (such as Nokia 510, 520, 610, 620) they can afford in eastern europe.
You see WP devices 'a lot' (that is: you get to see them once in a while) over there, but these are mostly owned by people who wanted some sort of smartphone. Also a lot of them are quite annoyed that there are no apps.
Except the argument was that the general public aren't fans of Windows phones, to which 20% market share of a few regions was used as a counter argument.
I would tend to think that market share is one indicator of a phone platform's popularity, and while 20% is not bad, it's not an amazing figure either.
I looked around for a chart of the iPhone's market share by year, but couldn't find one. I remember the iPhone having trouble in its first year or two, and most of WP8's credibility comes from the ~2 year old Lumia line.
True. In 2010 the iPhone only had about 4% market share. My only point is that I'm talking about popularity of existing devices. It may well be that Microsoft will turn it around!
The other way to look at it is that iPhone had ~100% share of the "modern smartphone" market (choose your own name for it, but Blackberries and Symbian don't count).
