Expedia Not the Same For Canadians?

I have recently been using Expedia to look for a vacation next March. While I have been searching, I noticed that using the Expedia.ca website would produce substantially less results for me than using Orbitz in terms of hotels. I thought this was odd, but I thought maybe expedia has different agreements with hotels than Orbitz. Anyways, so for example, a search of Rome hotels gave me 8 results with expedia.ca. However, I then tried the same search with expedia.com (the US website) and i got around 200 results! So while the Canadian site displays the price in Canadian dollars, and covers your trip with TICO insurance, I would use the expedia.com website to book trips outside of the US and Canada, or at least browse the US website first before booking.