The ancient agora became the medieval market square, and from the medieval market square grew the corner store, and the corner store was dwarfed by the shopping mall, and the shopping mall was demolished by Online retailing, so what, I wonder, will eventually supersede Online retailing? I'm no futurist, I'm barely even a presentist, but I have a few ideas.
Luxury goods, which will be the only goods worth buying, will be hand-delivered directly to the lunar estates of one-percenters by courier astronauts wearing zero gravity livery. The rest of us won't be able to afford such quality products and impeccable service, never mind the shipping costs from terrestrial warehouses to the moon.
We will still be residing back on Earth, herded into consumer-economy ghettos patrolled by an army of intrusive and persistent door-to-door robotic salesmen hawking nothing but cheap and disposable junk. An indestructible titanium foot wedged in our front doors will be much harder to dislodge than a human foot, and their pre-programmed digital sales patter much harder to resist. Buy one, get one, even if you don't want one, never mind two.
But on the bright side, when Online shopping is made obsolete by vending-bots and dealer-drones, perhaps the Internet might return to being a simple forum for exchanges of useful information and interesting ideas, and we can browse a web page about Heraclitus without being bombarded by advertisements for creature comforts. It's unlikely, I know, but I am an incurable optimist.