The Viability of Micro-Farms

At just 5.5 acres, I consider my farm small, especially considering that only about 2.5 acres of it is usable right now.  Things are just getting started, but I feel pretty confident that eventually, my small piece of land can provide 70% of required food for two adults.  My goal is to provide food, not to make a living.  Which begs the question, can micro farms do both?

I ran across an interesting post about the vaibility of small farms.  I thought the profit/acre anecdote was particularly interesting.  This is just a single datum point, but it is a datum point.