Generally speaking, building a print farm can be a pretty expensive investment. Starting out, you would need to buy anywhere from 10-20 machines and scale up your farm from there. But, 10 machines, at around $500 each, would result in pretty high upfront costs. So how can you get the scale of the printing farm to where you can produce 100's or even 1000's of pieces, without actually having to buy all of those machines?
Well that's why 3D printing farm services such as Slant 3D were created, so that as businesses are scaling up, instead of having to invest all that money into machines, they can just use the service to grow their customer base and be able to support those orders as they increase. Then once they hit those milestones and generate more revenue, they can then begin to buy more machines and begin printing in-house. This is a huge benefit because an internal print farm gives you much quicker control of the design, as well as, allows you to control your supply base. This limits the amount of delays and supply chain issues you may run into otherwise.