Whenever some one says to us please whatsapp me the details, we think twice because it takes more time then simply typing a message, you have to add the person in your contacts and then also it takes a while before it appears in the whatsapp contact, It is trouble some specially for businesses where we get many calls and people need whatsapp details and they are new customers.
There is actually a way to send a message to a whatsapp user without saving the number
WhatsApp provides a special url which if you place in chrome you can start a chat with any number that URL is
Replace the last part with the full number, with the country and region code, but without any + or – or () or 00.
For example if you want to message us (+92-321-2424778) you will type in chrome https://wa.me/923212424778
You’ll get the web page below with a big green Message icon. Tapping on it opens a conversation with that phone number in WhatsApp (if the number is registered on the service, obviously).