Once the app is tested and ready for launch, you have to implement a mechanism for making money of it. Be it the license generated on your own server, the yearly subscription, or In-App Purchase in the Mac App Store. These are two most popular ways which you may be interested in. Some professional apps implement both.
If you already configured Hockey and Sparkle for Beta distribution, then it is comparatively easy to add integration with a service like FastSpring to make money from the app. You have to implement safe storage for the license key as well and you are done.
If the app is expensive, you may want to implement some kind of Trial too. With FastSpring and license mechanism in place, this should not be a problem.
Mac App Store
Maybe your app is suited for Sandboxing, like 99% of all apps, and you don’t need a trial version. Then this distribution channel is a great option. Apple takes care of your builds and payments, and sure thing customers prefer to download apps “directly from Cupertino”.
However, there is a lot of work in iTunes Connect to be done. You should register the app, add metadata with pictures and descriptions in many languages, then configure the app for distribution using provisioning profile and certificate.
One more thing, the review and update process in the Mac App Store may become a nightmare, but in the end of the day, your app may be featured by Apple. Gotcha?
The last bit will be devoted to Marketing which I honestly have no clue about.