Just like in Real Life, we need new and alternative ways to commercialize our products and reinvent our businesses. I believe Second Life merchants as well as artists and independent developers would benefit from a subscription-like function that could be added to groups.
For example, customers would join a subscription-based store group and every month they would have a fee debited from their accounts which they could terminate by leaving said group. In return, they would have access to new releases instantly from their favorite stores. It would be interesting to have different tiers as well just like Linden has with "Plus, Premium and Premium Plus" within the same group allowing them to access more exclusive content based on their subscription levels.
Not only this would be a healthy way of energizing our economy by allowing creators to stabilize their income and feel more relaxed to be creative and give the best of their efforts towards their items, but it would also benefit customers who would have access to a lot more than they normally would, making their shopping less disposable and more enjoyable.
This is just an initial thought, feel free to add more suggestions in the comment section :)