• Industrial – This mode is common today, where high-quality, terribly expensive, difficult to operate fabbing devices are typically owned and operated by industrial designers, architectural firms and other professionals with the cash flow to support use of such complex equipment.
• Service Bureau – This is a newly emerging mode, where the price of equipment and media are low enough to support a burgeoning industry of service bureaus. These services accept or provide 3D models that can remotely print objects that are then physically transported to the recipient. The service is used when the client is unable to afford their own equipment, and will be popular with anybody who needs occasional 3D printing.
• Personal – This mode has not yet emerged, and will do so only when the price of equipment and media drop below a threshold for consumer adoption. What might that threshold be? We suspect it will be lowerer than the upcoming DesktopFactory device: US$5,000. In this mode home printers would appear and become common, and provide direct, onsite object printing for consumers.

Which is the correct mode? All of them! It depends on your circumstance as to which service is most appropriate. Just because you'd (theoretically) be able to afford your own 3D printer doesn't mean that you should buy one. Also, service bureaus will always be able to provide higher quality or faster output than home devices – at least for a very long time.