Hi,
I have used both Blog and Websites on same topic but in different manner.
Let me try to answer it with example:
Let us take an example of MLM concept (I know you all hate it but I love it

).
On my website I will tell people good features of my program and cost of products, benefits and all that stuff you put in a sales letter.
But then people have immediate question
"I am poor in telling people(nearby) to join my program and I have small group of friends, who hate MLM "
This is where I use blogs to tell them:
"the growth of MLM is not when you ask people(nearby) to join, it is due to the fact that how well you made a website and also optimization done by you. So that more traffic comes to you.
Remember in this world many people wants to join MLM because they have big circles to grow chain. Point is how to get them under you!."So website attracts the customer and Blogs acts as filler and helps me to calm people down. Simple isn't it.
Nikhil