Check out this informative video pointed out by electronics-lab.com.
By understanding the manufacturing process you will be able design PCBs that can made more easily and cheaply. Designing boards that fit within industry standard specifications gives you two advantages: you keep down the cost of your end product, so that it will sell better; and you improve its long-term reliability, so that your customers will keep on coming back to you. And when you want to push the boundaries of technology (and who doesn’t?) you can sit down with your chosen board manufacturer and discuss your requirements knowing where he is coming from.