It takes a lot of time, energy and money to start an online business. Not only do you have to be develop and maintain your domain expertise, but manage all the tools that make your business operate.
So when it comes to critical component like web development can become a difficult task to find the right web PHP Developers that understand how to write correctly web scripting. There are many approaches to this problem. You can hire interns. You can interview dozens of potential PHP Programmers.
Or you can go to a dedicated PHP Programmers expert like elance.com. They have done the screening of skilled PHP Developers. It's not rocket science. Unless your expertise is not programming. Then it might as well be a PHD Physics class.