Though my company is based in Canada, we have a .com URL, we're hosted on servers in the U.S., and most of our customers are in the U.S. Our marketing efforts are focused on the U.S. Heck, we even drop the "u" in "colour" and "favour"! 🙂 Nonetheless we rank very well in Google.ca, and rather poorly on Google.com. One hypothesis is that we have more backlinks from .ca domains than .com, but I don't believe that to be true. For sure, the highest quality links we have come from .coms like NYTimes.com. Any suggestions on how we can improve the .com rankings, other than keeping on with the link building?