A shop, that lets you overpay for goods you like, to invest the overpay into the companies that made them.
Would you overpay for your favorite food, like fish, potatoes, milk, rice, or whatever at a 10%, 25%, 50% above the base price, if you knew, that the overpay would automatically buy you shares of the maker of the product, so that in, say, 5 years, would you be able to get it for free, or get the dividends buy it? I definitely would, especially for my favorite products. It would automate my investment into companies that make the things I know I need, without any extra effort of investment portfolio management.
So, it's an idea of a competing supermarket, that buys goods from wholesalers, and through use of membership cards (popular loyalty cards), maintain investment portfolios for the customers. Surely, that type of supermarket would require for it to be a stock portfolio management company at the same time, so, two industries: retail trade + fund management.
Such supermarkets would have a social mission, to help people automate their lives. They would also be educational for kids, teaching them how to never have to pay for a favorite meal again.
Perhaps we could start such a supermarket chain: make money not just for ourselves, but for our customers. The idea is inspired by a previous idea: Consumer Investment Tax.
Retail buyers (consumers) buying out the producer stocks on a daily basis, as frequently as they eat/consume, does not seem to be very sustainable, because, although stocks are on the public markets for anyone to buy, they are actually a relatively scarce commodity, compared to the volume of retail trade.
However, if the said overpay would go to acquire stocks of not only the producer making the specific retail product, but also the stocks of the upstream supply chain companies contributing to the making of the said product, or, even the set of producers making equivalent products, then this would surely be more sustainable.
With time, I certainly would like to try that this idea. It's a no-brainer extra value to the consumer: shop for stocks of producers automatically, whenever you shop for ordinary consumer goods. Realizing this sort of thing would probably be most straightforward by acquiring a hedge fund, and a popular online retailer, with all the legal requirements already satisfied, then creating investment accounts with the hedge fund for all the shopping users, and sharing the investment money with the hedge fund. Such hedge fund's investing operations would be quite easy to automate, because the buying of stocks would be entirely deterministic, determined by the retail purchasing decisions.