When I first opened my shop, Pink Sunset Jewelry Designs, on Artfire, I only shipped within the US. My initial worry was the cost. How much is it going to cost me to ship to, say, Europe or Australia. What about customs, fees, taxes. Those fears kept me from offering shipping to anywhere but the US. When a customer shopping on my Vintage store (Back In Time Vintage Jewelry), requested to know if I would be willing to ship to the UK. I admitted to her that I was very green when it came to international shipping. I did tell her that I would research it and get back to her. Come to find out, that was just the push that I needed. And, in the end, it was rather painless. I sell small/light items, most under 5oz.(142 gms) so the shipping around the world was less than I expected. The next day, I recieved a sale from a lady in Germany.
It opened another world, literally, to my customer base. The views picked up rather quickly when I added International shipping. Think about it, research it at the US Postal Service website.
The second thing I am in the process of doing, is adding product sizes in metric. I have seen this requested by some folks on a forum thread. If Google is your search engine, you can just hover over the length or size and you will get a pop up with the conversion. But not everyone chooses Google as their browser. So I have been trying to update my site with the metric conversions in order to make it more informative for current and potential customers.
The bottom line is...listen to what potential customers say.