But if you're looking towards a majority, then it would be actively stupid to write off the entire area outside Bramela/whatever and Oshawa. You won't win the really affluent areas 'north' of the city, but humdrum suburbia certainly can vote for social democrats under the right circumstances.
But that's not what I was trying to address. I was explaining why the NDP in the 905 had been described as a "difficult" proposition. I never said it was impossible or that they couldn't win there with the right organization, particularly among South Asians.
As for Greater Vancouver, Earl is right that its NDP regions are considerably less wealthy than the 905 generally is. It's also important to note that, as far as I can tell, much of the NDP's strength there comes from organizational efforts over the years that have far surpassed those it's made in the 905. The point is that the 905 is particularly difficult ground in which to build a "wave" of NDP support.
North Vancouver's Liberal results in '04 and '06 can be pinned down to candidate selection. The Liberal, Don Bell, was a former mayor, while Conservative MP Ted White (in '04) and candidate Cindy Silver (in '06) alienated voters with social conservatism and indifference to the riding's large Iranian population.