100% this but the thing that's missing, is BBM's Pin feature. WhatsApp still don't have that. You used to be able to give out your pin and not your phone numb

100% this but the thing that's missing, is BBM's Pin feature. WhatsApp still don't have that. You used to be able to give out your pin and not your phone number and used to be able to sign up for mailing list / nightclub entry without your number passing anyone's hands.