Over half of Fortune 500 companies have their offices incorporated in Delaware. There are quite a few reasons to it.

Firstly, it is pretty cheap to incorporate in the American state of Delaware over many other states in USA. The state does not mandate that you be a resident of Delware to conduct business there. And if you are only going to incorporate there without any business specifically inside Delaware, you do not need to pay any tax (except for franchise tax). Also, the laws regarding unique individuals to hold different positions is not present in Delaware making it easier for small corps to set shop. Finally the infrastructure is great. Delaware has the best broadband penetration in USA.