Our high street chains are powerful selling machines. With exclusive access to some of Britain's biggest stores, Cherry Healey goes behind the scenes to find out how the sales work from the inside - so that we can all become savvier sale shoppers. Cherry goes backstage in the John Lewis summer sale, gets inside a critical mark down meeting where sale prices and sale strategy are set, and she discovers the addictive way bargain hunting can affect our bodies. Cherry also uncovers hidden sales offering huge price cuts, learns how major high street retailers use scent to try and influence our behaviour, and meets with a sofa manufacturer willing to admit furniture sales can be a psychological trick.