Currently there's no limit on the number of pieces you can self-launch. For one year (through June 2015), Minted storefronts will be in a "beta" period. This means that we will be experimenting to see what works for our customers and our sellers. During this first year, we will be suspending all listing fees. Take advantage of this beta period!
In order to maintain the ability to self-launch, we do ask that you stay present and active in the Minted community by submitting to at least 3 challenges every 12 months (preferably more of course!).