One of the key determinants of whether or not 3-D printing will hit the mainstream is price. In order to see a 3D Printer in every home the price would have to come down to under $200. It was around this price point that the laser and inkjet printers began to the exponential growth.
Currently 3-D printers cost about $500. Although this does not seem like it is a lot of money one must remember that these are still rather basic machines that do not have the design of consumer products like coffee maker or laptop computer.
The next determinant for 3-D printing will be ease-of-use. However it should be noted that the 3-D printers are largely of a do-it-yourself variety. In other words it is not a consumer friendly product. The software will not have a user interface that most consumers are used to. Furthermore, the 3-D editing software that is used to create an STL file is also out of the reach of most amateur technology hobbyists.
The last determinants that will dictate whether or not 3-D printing enters the mainstream is whether there will be any applications that will go mainstream. It can be as simple as a cool design for sunglasses that revolutionizes the industry or disrupting the food industry with 3-D printed food. Nonetheless, there needs to be an application that goes viral. Something must get into the imagination of the every average state consumer.
If one examines recent products that have gone viral they have all been priced under $200, easy-to-use with viral applications. Most recent example that comes to mind would be the iPod. This consumer devices price so that people from across the world whether it be in South America or Asia could purchase the product. Secondly billions of dollars was spent on research and development in order to make the device user friendly and more importantly to make the iTunes software user-friendly. Finally, there were applications that went viral as everybody quickly realized that this device had revolutionized music.