You design a little circuit and sell it online and you have to pay higher p ostage than to ship the product from China because the US is subsidizing th eir postage with epacket.
from Forbes:
"In 2011, the U.S. Postal Service made special agreements with the national postal carriers of China and Hong Kong (and subsequently South Korea and S ingapore) to allow tracking-enabled packages not exceeding 36? or w eighing over 4.4 pounds to be sent to the U.S. for extremely low rates. The y called this shipping option the ePacket, and the rates are so low that it 's cheaper to ship small parcels from China to an American city than it is to send that same parcel domestically."