This is very true. I can give another example(maybe bit-offtopic for HN).
A very good friend of mine worked in IT for like 10 yrs. He was quite good programmer, CTO etc. One day he decided to radically change his carrer and opened... 5 Subways in Eastern Europe (he is originally from there). FFW 2 yrs => his restaurants making him $400-500k/yr, he spends zero time managing them and just focused on opening new ones.
His lesson: IT industry has one of the hardest competition rates cause all super-smart geeks are competing on relatively small marktets. Other industries competition (esp in emerging markets) is seriously overrated.
Another example - my very stupid app for selling video files just crossed $1000/day mark in sales. Ppl just need simple tools to get things done.