Reasons to use 3D printing
So you are working a new product that you have created or your company wants to put into production. Traditionally the only option available would be processes like injection molding. But 3D printing has become an option for small to mid-level volume production of products. 3D printing eliminates the need for molds and allows for iteration of a product during production. If there is a problem with the design you just upload a new design and all products produced from then on are upgraded.
This flexibility and low start-up cost are really the main reasons to use 3D printing for production. Suppose you are the designer of a smartphone case. It has a beautiful swirling pattern to make your iPhone more sexy. To create a mold for that smartphone you would need to pay thousands of dollars. Then you have to sell thousands of those cases to pay for the mold. And you hope that you sell those cases before the new iPhone X comes out making your case obsolete. This is a very risky business to be in.
With 3D printing, much of the risk of creating something like an iPhone case is eliminated. There are no molds, you simply send over your design and in a few days you get back the product. There are also few volume constraints. You can order 10 or 10,000 and the cost per item will not be significantly different.
Here are some great examples of product and companies that can use 3D printing and the advantages of it.