I sell a Windows app. Americans may be only 11% of the population, but they're about 50% of my customer base. They buy licenses, which gives me incentive to continue working on the software. The Russian and Indian bloggers (for example) who have reviewed my app positively have moved the needle very slightly, if at all. No chance I'd give up my US customers willingly.

(Edit: I'm from South Africa, not the US.)