3D printers allow a company to produce a 3D model based on a design which they have completed on their own. They simply load this design into a 3D printer and it will immediately begin fashioning a 3D representation based on the design you have programmed.

If you were to attempt to use a third-party company to execute these types of model designs you could have to wait days or even weeks to receive your finished product.  But with 3D printers you can now limit this wait time to hours!   This will allow you to produce the 3D models that you need in the time that you dictate.
Additionally, this will also save you the expense of hiring a third-party model building team.  In fact, a 3D printer will generally pay for itself within the very first year of use!  That is why many companies are now investing in 3D printers in order to save themselves time and money.