While Android may be massively dominating iOS in terms of overall market share, when it comes to the amount of users each platform has online, the battle is actually evenly pitched.
According to Net Applications (via Forbes), in terms of mobile OS usage online, iOS holds a 44.2 per cent market share, with Android on 44.6 per cent – an almost dead even race.
Yet a recent blog post by Strategy Analytics showed that Android holds no less than an 85 per cent grip on smartphone market share, with iOS on 12 per cent (and Windows Phone on 2.7 per cent, incidentally) of the 295 million units shipped in Q2 of this year.
What this shows is while there are vastly more Android users, there's not a big percentage of them going online – a good deal of them probably just want a basic, functional, cheap smartphone, perhaps with no data plan – unlike iPhone users, far more of whom spend time online (probably almost all of them).
Which means that despite the overall mobile OS market share looking like a hopeless one horse race on the face of it, from an advertiser (and developer) perspective, iOS still carries a lot of weight in terms of quality, if not quantity.
That said, this is actually the first time Android has bested iOS (just) as measured by Net Applications, so the tide could be slowly turning yet.
The other concern folks have about Android, traditionally, is on the security front compared to iOS – but as long as you stick to Google Play for apps, that's not a major worry. And also Apple has been hauled over the coals on the privacy and security front recently, as well, but for different reasons other than malware infections...