The reasonably insightful comment on reddit was that this isn't just a pissing contest between MS and Apple - it's a pissing contest between Crispin Porter and

The reasonably insightful comment on reddit was that this isn't just a pissing contest between MS and Apple - it's a pissing contest between Crispin Porter and TBWA (the ad agencies)... I think one has the more appealing product to market, the other has the bigger budget and the defensive position. It's a fairly textbook marketing battle between the entrenched number one and the upstart niche player.