I personally think they are making a mistake. There is a very big percentage of every route that relies on connecting passengers. And being that they are that close to LAX, connections aren't so necessary.
Similar to the not-very-succesful BOS route where people can connect via NYC. Seriously, how many passengers on the BOS flight are actually originating/finishing in BOS? 20-30%? On the NYC route it's probably more like 80%. Even LAX and YYZ, I'd assume that more than 50% of passengers are not connecting. But is there really that much demand for non-stop to/from SFO after UA already operates a daily flight on the route?
Just MHO