You have to deal with taxation. As a minimum, for EU customers they'd have to extend the same VAT arrangements they give to Swedes, whereas any non-EU customer would get different tariffs, and you have to make sure it's all accounted properly.
Then they'd have to look at other laws and regulations for cross-border businesses, and would likely have to pay higher premiums for their insurance against lawsuits for hosting "bad" content. Also they'd need a lawyer who understands all this, rather than your average small-time small-biz paper monkey.
EDIT: and of course, you have to support international payments through VISA or equivalent on your website, which is a pain in itself.
>For the EU taxation there is no tax if the customer is outside EU, this can be resolved by CC address.
Yeah, what I'm saying is that their payment processor must then understand three different categories of customers (Swedish, EU, non-EU). You'd be surprised how many small operations struggle to just put in place a decent payment/accounting platform ("It's just a few sums, I'll code it in an afternoon, no need to buy $expensiveButComprehensiveAccountingSoftware !"...). And of course, currency conversion between Kroner and €, £, $...
You'd also be surprised by how many regulations we have in Europe covering money transfers -- internal credit cards, external credit cards (yes, often they're different things), debit cards, prepaid cards, all regulated by laws that vary State by State, and all handled by banks through byzantine merchant contracts. I'm not 100% familiar with the Swedish system, but I do see the difficulties in handling foreign payments.
Then they'd have to look at other laws and regulations for cross-border businesses, and would likely have to pay higher premiums for their insurance against lawsuits for hosting "bad" content. Also they'd need a lawyer who understands all this, rather than your average small-time small-biz paper monkey.
EDIT: and of course, you have to support international payments through VISA or equivalent on your website, which is a pain in itself.