How to do effective business development?

Successful business development fetches sales and sales bring money.
Here is the strategy you need to know about good business development online.
1- Knowledge about the product or service
2- Don't be afraid
3- Create Rapport
4- Always ask, don't tell much about yourself unless asked by the client.
5- Always offer something (Mockup, etc)
6- If PMB opens or client sents a message (Always follow up)
7- Sale begins after the deal is done (results in long term client retention)