Friendship based on a business relationship lasts longer than a business relationship based on friendship.
It is not advisable to do business with friends. Generally, there are no calculations in friendship. But, when a business relationship starts, calculations come into picture, which create misunderstandings sometimes.
On the contrary, if there is a business relationship with someone and then it leads to friendship, that relationship has a higher chances of success.
(Expert advice to GROW your business wherever you are, whenever you want.