If you want business-class cabins, lounge-access and the-like that's true but obviously the gain of domestic market-share by Westjet and Porter isn't simply leisure travelers, although AC certainly has a larger share of that market.

http://www.statcan.gc.ca/pub/51-004-...3/t013-eng.htm

From Statscan: (from 2009, last time they did this nice summary text on market share, but Westjet has increased its share since).
"For the 12-month period, January to December 2009, WestJet continued to gain market share, in terms of passenger traffic, in international scheduled services and slightly lost market share to Air Canada, in domestic scheduled services. During the period, WestJet transported 50.1% of domestic passengers and 18.9% of international passengers. Comparable figures for the 2008 period were respectively 50.8% and 14.5%. However, Air Canada still dominated the domestic sector in terms of passenger-kilometres with 57.8% of the market (see Table 2). (Note: market share is measured here with respect to these two carriers' operations only.)"