I noticed (thanks Twitterverse) that there was an interview with Rex Black over on the UTest blog. In that interview he reveals a very interesting number:
"...the ISTQB has issued over 160,000 certifications in the last ten years."
Using the numbers from my previous post: if we assume that there are about 3,000,000 software testers in the world right now, and if we issued 160,000 certifications right now, that would mean about 5 certifications for every 100 software testers.
I would be willing to bet that there were about the same number of testers ten years ago: Y2K was just over and the value of dedicated testers had been shown. But as Alan Page and others have noted, there is a lot of turnover, a lot of churn, among those practicing software testing.
So my numbers start to get a little sketchy here, I don't have anything to back them, so consider this a thought experiment: as noted above, let's say that there were about 3 million testers a decade ago and there are still 3 million testers today. Let's say half of today's testers have started since 2000. This gives us a field of 4.5 million testers who could have acquired a certification in the last decade. This makes for about 3 certified testers for every 100 possible certifications.
I think it is an excellent bet that a significant fraction of those 160,000 certifications were issued in the UK, Australia, and New Zealand. Just to make it even, call it about 1/3, put 60,000 certs in those regions, leaving 100,000 for the rest of the world. That brings us down to about 2 certs per 100 testers.
But that still seems high to me. I might have missed something. Regardless, it still looks like a pretty small market, and I'd bet the market has been shrinking a lot with the rise of agile adoption and the economic downturn.