Ask HN: Does Facebook Use WhatsApp Data for Trends/Analytics/Ads?

According to WhatsApp Blog

"Remember, when advertising is involved you the user are the product.

At WhatsApp, our engineers spend all their time fixing bugs, adding new features and ironing out all the little intricacies in our task of bringing rich, affordable, reliable messaging to every phone in the world. That's our product and that's our passion. Your data isn't even in the picture. We are simply not interested in any of it."

https://blog.whatsapp.com/245/Why-we-dont-sell-ads