1. If you hire three ex-engineers, your product has no gurantee.
2. if you outsource to IBM, your product is gurantee.
3. If you hire contract employees, once the contract is over, they are gone.
4. if you outsource to IBM, if there are bugs, you can call them to fix it, free of charge since it's IBM's problem.
5. If you hire three ex-engineers, your product is developed among these 3 people.
6. if you outsource, your product is developed by a team of tester, designer, programmer, that fulfill the whole software cycle.
..etc...