NEW DELHI: WhatsApp on Thursday updated its privacy policy for the first time after it became a part of Facebook, outlining the ways in which businesses will be able to create more targeted advertising on Facebook using WhatsApp.Speaking to ET, a WhatsApp spokesperson explained how this will work. When a person signs up on WhatsApp, they provide their phone number as an identifier, and a unique number that is associated with the device (such as smartphone or tablet) that the WhatsApp app is installed on.If a person has the Facebook app and WhatsApp app installed on the same device, even with different phone numbers, by using the device identifier, Facebook will now be able to map the two in the background using the basic device information.WhatsApp hopes to better fight spam with this integration. “For example, if someone is using Facebook in abusive fashion , sending malicious links to users and we are able to identify that account also on WhatsApp, we can disable that account and its services rather than just on Facebook,” the spokesperson added.This also means that if you have some friends on WhatsApp who are not on your friend’s list on Facebook, you could now see them as “friend suggestions” on the social network.The other part of the update will be to enable more targeted advertising for businesses, mainly through an existing Facebook advertising platform called “custom audiences,” which will be able to show more “relevant ads” by mapping Facebook and WhatsApp numbers.“For example, 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,” the spokesperson explained.This is possible because the shop owner can upload a contact list when creating an advertisement and this information gets transformed into codes by a process called hashing, 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 said.The user can, however, choose to not let WhatsApp share information with Facebook. “"You can opt out of sharing information from WhatsApp to Facebook for any sort of products or ad experience on Facebook," the WhatsApp spokesperson said. Users will receive a WhatsApp notification on their app beginning Thursday evening, as the new features roll out worldwide, and can then choose how they want their data to be used.The new policy will also take on spam more actively and use WhatsApp's integration with Facebook for better friend suggestions and drive greater reach for businesses.The privacy policy update, which is the first in four years, also reflected the recent changes and additions WhatsApp has made to its product in these years, such as end-to-end encryption , WhatsApp Calling, and messaging tools like WhatsApp for web and desktop.The policy update stresses that the messaging app will not “post or share your WhatsApp number with others, including on Facebook, and we still won't sell, share, or give your phone number to advertisers,” it said in a blogpost on Thursday evening.“But 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,” it added.Essentially, while WhatsApp will continue to remain ad-free, its integration with Facebook will ensure that businesses get wider reach through the social network and send more targeted ads to potential customers.The company stressed on the fact that a user’s “phone number will not be shared on Facebook or with third parties, nor will messages or any type of front-end you choose to share on WhatsApp”.