[ctrl_freak]

As brilliantcode mentioned, Facebook, Microsoft et al are using Vancouver as a visa staging ground for people outside of North America. Most Canadian software engineers can work in the US on the TN (which doesn't have a cap like the H-1B) so they don't have visa issues. They bring them over to Vancouver, basically training them there, and once they've worked there for a year, they're eligible to use the L-1 visa, because it's considered an intra-company transfer, so they can move them into the US.

The Vancouver offices are not an investment in the Canadian tech industry; they're just taking advantage of our more lenient immigration laws and the convenience of the city being geographically close to San Francisco. Waterloo and Toronto seem to be taken much more seriously as remote engineering offices for American companies (possibly because of the universities and amount of tech talent in the region).

It's kind of a shame though. Vancouver is a beautiful city, conveniently located, and there's no good reason why it couldn't be Silicon Valley of the north. If they could just figure out how to make it more economical to live there for software engineers (i.e. cheaper housing and higher salaries), it could quickly become a booming tech hub.