Given the popularity but also the typical churn of additions like these i think it would be useful to allow people to submit a request for unused (but claimed) spots in the commercial districts.
I understand currently it is all very new so this is not an immediate suggestion, but having some way, in a few weeks / months time to be able to stake a claim to a store that has not been utilised after being claimed would also help active people who are really interested in sharing their creations in these spots to gain the ability to do so, that were previously unable to.
Perhaps a system similar to the method used for being able to have abandoned land portioned off to claim?