Here is the snap shot of the final panel of the ad:

Decide? Decide how? There isn't an election on right now, and won't be for several months, at the earliest.
And the most important reason to vote NDP, based on the design of the panel and the emphasis used, is to stop Stephen Harper.
OK, how will the NDP stop Stephen Harper? I click on the ad and go to this page that repeats the final panel (in a widescreen format) minus the strange "You Decide" text. This is not the home page for the NDP site, but a special page to which the ad is directed. We call that a splash page. Here is what bothers me about this page:
A splash page needs to reward you for clicking the ad, not leave you wondering if you came to the right place. To get to the actual information related to this ad, you need to click again. That's a mistake right there. Indeed, you have to click the ad image a second time (Why? I already clicked it on the Globe and Mail page), or click the small "Learn more" anchor underneath the ad.
When you do, you are taken to another page, this time enumerating the NDP platform on the environment, seniors, child care for average families (the poor and the rich can go elsewhere, I suppose), veterans, and education. Stephen Harper and Conservative government policy is mentioned only once under the environment. On the surface, it is not clear how the Conservatives need stopping on any of the other issues. Indeed, in the case of veterans, the NDP proudly announces how it got unanimous approval for a state funeral for Canada's last WWI veteran -- clearly the Conservatives did not need to be stopped.
So the ad content, which took two clicks and too much thinking to reach, fails to deliver on the promise of explaining why Stephen Harper needs to be stopped, what it is about the NDP that puts Jack Layton in a position to stop him, and most importantly, what decision I am being called on to make.
Again, the title of the page is "NDP |", which doesn't tell me that this is the page where I'm going to learn how my decision is going to stop Stephen Harper.
All in all, not a great ad campaign, either technically, or in content. Perhaps the NDP is running it now as a test, to evaluate reaction. If so, here are my recommendations:
Web-advertising is like advertising anywhere else. The ad makes a promise to those who decide to do what the ad suggests (follow a link, enter a store, watch a television program, whatever). People who take the time to respond to an ad are waiting for that promise to be fulfilled, and they will be angry if that doesn't happen. For a political party to not fulfill the promise of an ad is a bad thing, since it does not bode well for the party fulfilling promises in general should they ever win an election.