We've made it from your connection to Edmonton, now the data is outside of the MCSNet network and has to get to the different servers around the world connecting to the Internet. The Internet is a patch work of interconnected networks, and the data will take the shortest (fastest) route to get to the destination. The speed of the connection still depends on the responsiveness of the route.
If you are connecting to major services like Google or Microsoft, they are more likely to have direct and large pipes to their data to provide fast and uninhibited access. For example, opening a youtube video, which is a google service, will in many cases hit a cache in St. Paul, or go through a larger fibre almost directly to a major Seattle data center. Alternatively, if you go to a smaller site hosted in the UK, it has to make it through a few networks in North America before going through the undersea cables, and through their local providers feed, which will be more susceptible to latency and limited bandwidth and peak time issues. Even the major sites are not immune to issues, denial of service (DOS) attacks to overload networks and servers are common, and services like playstation and xbox are still going down during busy holiday times when more people are using it.
The Internet connects you to the world, but a connection to Edmonton will still be faster than a connection to Sydney
If the rest of the Internet is fast and just facebook is slow, then it's simply because facebook itself is slow, it has its moments. There was some finger pointing at Netflix about the growing slower rates of the Internet, but that's only because Netflix is the best at providing streaming video service. We hear a lot of complaints about other streaming video services like Shaw on Demand hardly working at all for unknown reasons; Netflix is awesome compared to some of the half-baked copycat services.
If the purpose of a speed test is to test the speed of your MCSNet connection, then you want to eliminate any possible source of slowness in your network as well as in the Internet network.
If we take your network and the MCSNet network out of it, you will still get varying results from different speed test servers around the Internet because of the different distances/capacity/activity. A speed test that works great in the States might not provide any consistent results in Canada. If the data has to go through more and more networks to reach its destination, it's more and more likely to be affected by these far away networks that you, or MCSNet, have no control over. The purpose of a speed test is to test your local connection, we want to leave performance the issues of the corners of the Internet out of it as much as possible. The speed test on the MCSNet site is speedtest.net mini, so it's the same test as speedtest.net, except hosted in St. Paul. The Edmonton servers on speedtest.net are also good tests. Bad tests would be to servers like testmy.net, where the traffic has to wade through some cowpokes to get to their default server in Texas.
For testing the MCSNet connection, use the MCSNet speedtest page