Launching an app in the App Store is a great achievement, but you’ll be flying blind with just the sales metrics provided by iTunes Connect.
Inevitably, there will be issues you’ll want to track, real-time user metrics, and a broader understanding of the device population that you’re deployed to.
There are a couple of startups tackling this problem, and I definitely suggest you check out their lightweight SDKs and integrate one with your application. There’s a great similarity across what they are all offering — a few logging methods and a web-based dashboard reporting the results. Most even take advantage of CoreLocation to report back the geographic distribution of your user base.
We’ve been using mobclix to accomplish this, and in general, it’s a good offering. All of this is new, so I wouldn’t get too carried away with your expectations, but this begins to fill the void that Apple has so far not addressed.
One of our home dashboards in mobclix:

gives us an instant breakdown of how many users on what devices and what their primary means of connection (wifi, carrier, none) is. We’ve chosen not to track their location, though, as this application doesn’t use CoreLocation
So, when planning your rollout, considering the easy integration of one of these offerings:
My name is Peter and I work for Flurry. Whether a developer goes with our service, or another listed here, I agree with Dave that tracking metrics to understand your consumer behavior and how your application performs on a device. My career has been in product management and marketing, and creating a data driven development process, based on tracking customer actions, can help a company tremendously. Thanks for including us in the round-up, Dave. Best regards, Peter