Amazon lockers offer a solution for Amazon only products. This is an open platform all carriers to use, in addition to the other 70% of eCommerce sales in Canada.
For a long time Amazon fulfilled only their own products (and some large partners) from their warehouses. Now, it's offered to everyone as Fulfillment by Amazon service. No doubt Amazon will offer the locker service, if the market is there.
You're right. Their marketplace model has been built out. Amazon's use of the locker system is an incredible opportunity and as exceptional validation of the technology.