shipping container storage

[Joshua Chapin]

Hello I am hoping to gain some knowledge and or insight in using shipping containers for mini storage. This idea has come up because my father is currently doing the same thing. His containers are on the same property as his small business and he does it on the side for extra cash. 15 or so containers and at least 12 are full at all times. 

What are your thoughts on doing this? Any potential problems I am not seeing?

Thank you -Josh