Looks like the preemptive ticket sales for the Conference Semifinals (read: MLS Cup Quarterfinals) worked, at least in part, as all signs point to the Cathedral of American Soccer selling out for the first leg of the 1 Percent Derby.
An email from Fan Services said they're "anticipating a sell-out crowd" and are suggesting "fans give themselves a little more time to get to the arena" (also from that email: "If it has a sign that says 'you will get towed', most likely you will get towed.") As of this writing, the "best available seat" online is the very last row in 227. Heaping some anecdotal evidence onto the development, as of Friday afternoon, the lower bowl was sold out, with only 200-level seats available (alas, I had to get tickets for 203, instead of the South Ward).
Aside from the impressive feat of just abotu selling out a 25,000+ seat stadium in a handful of days, this goes along way in helping to answer the question plenty have asked as the team struggles to garner attention in the country's biggest market: What does MLS have to do to appeal to New Yorkers?
Star power aside - and the two teams certainly have that - I think the answer is obvious. Win.