There is a lot of confusion as to what information from WhatsApp is being used by Facebook to show advertisements and how it uses the information. In fact, there is an ongoing case in the Supreme Court of India on WhatsApp’s privacy policies. We reached out to WhatsApp and Facebook for an answer and here’s what we got.
In WhatsApp’s page regarding its policy changes, it’s mentioned that the company works together with Facebook to “improve our services and offerings, like fighting spam across apps, making product suggestions, and showing relevant offers and ads on Facebook.” This raises the question as to what information from WhatsApp does Facebook use to show advertisements?
In response to this, a WhatsApp spokesperson referenced an earlier blog post which stated, “by coordinating more with Facebook, we'll be able to do things like track basic metrics about how often people use our services and better fight spam on WhatsApp. And by connecting your phone number with Facebook's systems, Facebook can offer better friend suggestions and show you more relevant ads if you have an account with them.”
The spokesperson also gave an example of how this works. “if you sign up to your local flower shop's mailing list using the same mobile phone number that you use for your WhatsApp account, and they decide to advertise on Facebook, you may see their ads on Facebook. This is possible because the shop owner can upload a contact list when creating an ad and this info gets transformed into codes, so Facebook doesn't receive actual contact details from the advertiser. On Facebook's end we help the shop owner understand how people interacted with their ad but we don’t tell them who you are.” The spokesperson notes that this product is called Custom Audiences.
In other words, when a merchant, with your details in its mailing list, decides to advertise on Facebook, the merchant has the option to upload a contact list. This list is then changed into code, which is then used to show targeted advertisements of that merchant. So it seems like Facebook doesn’t actually get your contact details from WhatsApp, just some codes.