For example, if I'm targeting Australia only, I use '.com.au' and find it MUCH easier to rank in Australia. I then have a difficult time expanding Internationally with that website however. You need to look at your long-term goals. Is there enough traffic in your native country? Do you believe you have the ability to dominate a global market? I've found with some niches it was just worth easily dominating the local, because globally it was too competitive, and there was plenty of local traffic.