How many people paid for WhatsApp?

A few hours ago we echoed from which is poised to be one of the news of the week: WhatsApp left to charge 99 cents a year that was set as “standard” rate (and I say “standard” because not everyone had to pay). But there are people who really paid? That seems to have been one of the most repeated questions during the last hours and, although it is not easy to answer, we can say that the answer is yes.