When Whatsapp was released, free text messaging was not a thing for most of europe. The USA had long since ditched charging for sms messaging by that point, so

When Whatsapp was released, free text messaging was not a thing for most of europe. The USA had long since ditched charging for sms messaging by that point, so the attractiveness of a free communications app wasn't there. Also, there are carriers in europe that offer bundle discounts and better data packages for opting out of sms altogether.