With WhatsApp Business you can label your contacts and create a pipeline for your sales team.
If you use Labels with WhatsApp Business you can organize your contacts and move them very quickly in a sales funnel.
One amazing feature you have only for the Android version of WhatsApp Business is to send a message to all your contacts under one label.
This is a feature missing in the iPhone version that we hope eventually will be updated. But for now, you can not send a message to all your contacts with the same label. You can do it using Android.
Just remember all the contacts you have in your phone MUST have you in their phone as a contact to get your message. Otherwise, your message will be not deliver.
And if you do this type of actions frequently you will end up loosing your WhatsApp number. So please be nice, create value for your customers and give them some content they want to read.