But how many big companies are there that do a significantly amount of their IT business in Perl? I don't think there are many. Let's multiply the revenue of a company with the fraction of their IT work done in Perl (to not have the amounts dwindle to nothing, only consider their in-house produce, and what was tailor made externally). For how many companies will this product reach 1 billion USD/year? Not many, I'm afraid.

Won't that filtering mechanism filter out most technologies? Seems like a good way to get wrong figures.