With trademarks, typically the first to use the mark will have superior rights over any other, later parties who try to use the mark (or a similar mark). This is complicated a bit by registration and international law (or, more specifically, whatever the intellectual property laws are like in other countries).
For example, there’s been some press about Groupon’s advance across the globe, and how it hit a snag in Australia. There, a company snapped up some Australian country code domain names using the Groupon name, as well as an Australian trademark Groupon Pty Ltd. This forced Groupon to launch in Australia under a different name, and try to use the legal system to force the prior registrants to give up both the trademark registration and the domain name.
It didn’t work. Ultimately, Groupon reached a settlement with the guys who beat them to the punch.
Earlier this year Groupon’s CEO Andrew Mason said he was willing to pay $US286,000 to the brothers. That offer was rejected so one would assume that the final settlement figure is higher than that.
If you’re thinking about expanding internationally, you should be proactive and quiet about it. After all, trademark registrations (and domain names) are generally very inexpensive, though some ccTLDs are pricey and have strict local requirements that gTLDs do not.
Of course, this advice applies to local businesses as well. Register your trademark! And contact a trademark lawyer to help you with the branding on the front end, before you file, because you may find the great name you’ve decided to use for your shop has already been taken by someone else for the same purpose. If you opt not to do that, you may find yourself in a similar situation to Groupon, with potentially lots of money and customers at stake and someone on the other side holding out their hand for a large cash payment.