For SM efforts by concerns within the U.S., those that do business within the U.S., contiguous or not, is it generally worthwhile to engage with Overseas/Canada/Mexico, entities?

In the case of sites deriving revenue from advertisers, including Adsense (having advertisers or businesses that only ship or deal within the country) I beleive they are able to auto-detect site user locale when presenting ads. But can too many 'out of the country' site users be cause for the advertisers to opt out of advertising on select sites altogether? Then there are the private paid-fors to consider.

Balancing this, against the out of the country SM businsses whose % of followers/likers/etc happen to be within the country -- this all seems too undefined to foretell.

So is limiting to within geographical limits of whoever in-turn supports a given site or account a logical or preferential avenue to pursue?