You could also be hiring a guy who does marketing to help you get more customers, give some other guy a sales commission for sending work your way, and so forth.

These things don't always require formal structures. You have more power as one who is self-employed rather than an employee.

The fact is there is nothing limiting this advice to developers. If you know how to do bookkeeping, for example, you can become self-employed and rent out your services to customers rather than having them hire an employee.