The price labels on supermarket shelf edges are little OLED screens, displaying spot prices for the goods. Prices are controlled by a humungous central computer network owned by the supermarket HQ, and are updated every 3 seconds.
Prices are adjusted according to as many factors as the supermarket accountants can think of including weather, stock levels, currency fluctuations, commodity prices (including oil), wages, number of customers counted in each aisle (by remote sensing devices wired into the system), purchase history of each product, etc.
When the item is placed into the shopper’s trolley, its tag is automatically scanned and recorded on the customer’s account. Payment can also then be automated and a final receipt issued showing the price paid for each item.-- pocmloc, Jun 13 2010 [Ian Tindale] It's not just a market ... it's a SUPERmarket. Like an auction, it'd probably get people to buy things they don't even *want* let alone need.-- mouseposture, Jun 13 2010 hmmm, neat, but you'll have a lot of restocking to do as people see the person in front of them paying less for the same product I think.-- 2 fries shy of a happy meal, Jun 13 2010 Prices of goods that fluctuate rapidly are just as bad as an unstable currency. People like to have an idea of what their money can buy them.-- rcarty, Jun 13 2010 [2 fries], this is why the good is scanned into your trolley. That way, if you decide later that you no longer want the item, you still have to pay any difference if the spot price has dropped.
[21Q] you have impressively hi-tech farmers if they use this system at the farmer’s market! Don't the pricing screens and networked servers stop working if there is a rain shower? Do they bring generator trucks to power the setup?-- pocmloc, Jun 14 2010 Supermarkets (in the UK) are already talking about doing this but in a much more dynamic way. Shoppers will have RFID-enabled loyalty cards which will be detected by the pricing displays on the shelves, so that, as you approach the shelf the prices will change to show special prices and offers only available to you, based on your previous shopping history.-- hippo, Jun 14 2010 The example quoted in the tagline //58p... 57.8p... 57.3p... 56.9p - grab two tins quick!// is counter-intuitive. If the price of something is dropping, normally you'd expect people to anticipate it to continue along the same pattern - so dropping prices would cause people to hold off, while rising prices 10p...15p....20p etc might encourage them to buy now, before the price skyrockets upwards any further.
Schoolkids could hang out in aisles, taking items off the shelves at high-prices, and putting them back at low prices, presumably generating a profit in the process.
And how would you avoid spivs and the like engaging in inter-trolley trading?-- zen_tom, Jun 14 2010 Supermarkets would also have to set up derivatives markets so that if you wanted to lessen your exposure to price fluctuations while shopping, you would be able to buy a selection of call options on the most price-volatile items on your way in to the supermarket.-- hippo, Jun 14 2010 I just want a loaf of bread and a pint of milk. If I wanted to play the market, I'd be trading stocks and shares like the other zero productivity parasites.
Smelly fishbone.-- Twizz, Jun 14 2010 random, halfbakery