It's just where your package gets shipped from. The further you are from the shipping point, generally, the more money it cost to ship an item. More shipping centers means more people are close to one. A kickstarter specific fulfillment center means the company you backed a project with doesn't normally ship from that location and they are pay another company to handle that portion of the shipping.
I see, fulfillment centers are like "hubs" to forward the game in bulk once received from the place of manufacture.
If one does not live in a country with a fulfillment center then the shipping is much more expensive. If you live in an obscure or not covered country you may be the only one to receive it, thus the high shipping. That's the way I read it.