Because it's a niche?
I know someone who used to work at B2B computer equipment reseller company. They were three people. The owner (doing accounting, planning etc.), a sales guy and one maintaining the warehouse / packing. Some days they would ship out 5-10 pallets of goods. On busy days, the owner and the sales guy would help out with the packing/shipping as well. Amigakit also does repairs, and one tech could probably manage that, which would make it four people required.
You may know several people who have bought from them, but most of their customers are probably active in Amiga forums.