I assume in US? Here in India i doubt many know if there is something called Snapchat or even Instagram. Everyone's on WhatsApp.
Snapchat on the other hand, most people won't know about it. However, I bet its drastically going to change in two years. Whatsapp is basically an SMS replacement - it lacks media rich features and as mobile internet speeds improve in India, people will gravitate towards apps such as Snapchat.