Political Attack Ads: Playing to the lowest common denominator

So neither the Conservatives nor the Liberals say they want a federal election this spring. And yet, both have spent the better part of the last two weeks firing salvos across the bow of each party's ship so to speak with attack ads usually reserved for election campaigns.
Stephen Harper's Conservative's got the ball rolling with a series of ads attacking Liberal Michael Ignatieff - Conservative Attack Ads - before the Liberals fired back with  a shot of their own - Liberal Attack Ad.
But at the end of the day what is the nature, the purpose, the point of an attack ad? Is it simply to point out the flaws or voting record of an opponent? Or is it a desperate hope that the electorate that you're playing to is so stupid they won't recognize the misquoted, taken out of context, years-old footage, used to make the ads look somehow relevant to them?
For years politicians north of the border have, by and large, taken the high road to their American cousins to the south who take attack ads to a whole new level.
But it seems with too many failed attempts by Harper to end up with anything better than a minority government, and Ignatieff's lacklustre showings - and the Liberal parties for that matter since Jean Chretien stepped down - both sides are looking for an edge that will cast them in a better light with the electorate; even if that means offering nothing more than why the opposition is the worse choice.
Politics is a funny business. In an idealistic world it would be nice for different parties to present different views and leaving the electorate to make up their own minds; but I suppose some things are too important to leave to chance, and to the electorate.
Attack ads while undeniably effective - to a degree - are also a parties own worst enemy and the easy, cheap points gained by such tactics, are come at a cost.
The only question now will be if either Harper or Ignatieff will see enough in their internal polling numbers to pull the trigger on a snap spring election, and whether their attacks win more friends than they lose.
Stay tuned and time will tell.