Why can't some international customers purchase PDF Downloads?

[ASeller]

I am in the US.  Customers from several foreign countries have told me that that they are unable to purchase PDF Downloads from my website.  Sweden is one such country.  These PDF products are in General Shipping, which is where Items that don't require shipping automatically fall.  However, General Shipping allows international shipping only to Australia, Canada, New Zealand, Switzerland, United Kingdom without using the Markets app (which opens up a whole different can of worms). 

Is this why some countries can't purchase PDF products that don't require shipping?

Have you found a remedy to allow buyers worldwide to purchase PDF products?

Thank you.