Because it is more cheaper and you no need to hire developers. Due to outsource much easy to find experts for development solution can read more. I recommend that you find all the information useful information and how to avoid big troubles. Also, you will understand how it works software business.
That's a really big question! I think of the first things people outsource is accounting, but really it comes down to two things:
1. What knowledge/skills does a business owner lack?
2. Will their time be most effective learning a new skill like web development, or serving their customers.