>The last point point about being a continent is that I can ship across the USA for far less than I can ship from one side of the EU to the other.

I sell on eBay and Amazon. We Americans have no idea how good we have it in terms of shipping options.

I can ship via USPS a videogame that is, including the padded envelope, 4 oz or less in weight for ~$3 to anywhere in the US (even AK, HI, and PR and other territories).

I can ship as much as fits into a USPS-provided free padded Priority Mail envelope for $7.75, and reasonably expect that it will arrive anywhere in the US in two to three days.

After FedEx ended its relationship with Amazon, it gave eBay Amazon's previous steep discount. In many cases, FedEx 2Day through eBay is by far the cheapest way to get a package from one US coast to the other, even cheaper than USPS Priority Mail and Priority Mail Cubic. This is guaranteed two days or less, as opposed to Priority Mail; think SLA versus lack of same.

Such a discount is available to others, of course. I've written before about how I a month ago made $1700 in profit in three days by dropshipping a popular video game-related accessory from its manufacturer to dozens of customers around the country. I leveraged the manufacturer offering free FedEx shipping to fulfill my orders.