Canada, with a population about one-tenth the size of the US, also has a significantly smaller business-to-consumer ecommerce market. This year, eMarketer estimates, online sales of retail and travel products will reach $21.45 billion in the country, compared to $343.43 billion in the States.

That gives Canada a 2% share of all B2C ecommerce sales around the world, or 5.9% of the market in North America. And while its worldwide share will drop slightly in coming years as emerging economies grow their online sales rapidly, Canada will gain share in its home continent as sales grow faster than in the US.

This year, growth in B2C ecommerce sales in Canada will outpace the US, at 14.3% vs. 13.8%, and Canada will widen that gap in coming years. Online sales in Canada have some catching up to do—the market is not as mature as in the US, where a long history of catalog sales, better shipping infrastructure and other factors made online buying a fast friend to many consumers.

eMarketer estimates that this year, 71.6% of internet users in the US will make a purchase online, compared with 60.8% of web users in Canada. By 2016, penetration in the US will rise by less than 6 percentage points to 77%, while the reach of online buying in Canada will go up more than 9 points to 70.1%.