WhatsApp with you ?

Disturbing news: FaceBook might be interested in buying WhatsApp. The question is of course what FB is after. If all they need is the long list of WA users, WA won't be long for this world. If they truly want to continue to provide the WA service, the concern raised at the end of this piece is quite right: how will free and advertising-driven FB deal with the advertising-free and not so free app model that drives WA ? Could make for a messy marriage.