My 2 cents........
It works with Business associates who become good personal friends.
But bringing friends into business , does not.
Doing business with a family member?
Well me and my brother Technick started off in this business together and 8/9 yrs later our relationship has not suffered.
In fact being brothers , we believe, it is what gives us an advantage.
And everyone knows Ant and I still do a great deal of business together after 6 years.
I actually prefer dealing in business with people I have got to know.
Look at Oprano...most of us have known each other for years.