Seattle is the testing ground as Amazon eyes its next big idea

The retail giant is expanding into the physical world with a series of trials in its home town. First came a book shop, but the real prize is in groceryThe buzz of a text message heralds the latest offer on Amazon’s Treasure Truck – a funky lorry bedecked with funfair lights and retro signs that appears at random in the streets of Seattle with a one-off discounted product for sale.Alaskan cod, four fillets for $17, was the most recent item; a few days earlier it was two 16oz prime st