► Subscribe to the Financial Times on YouTube: http://bit.ly/FTimeSubs<br /><br />The only reason many of us still have wallets is because we need a place to keep store cards – but are any of them really worth having? Understanding how big retailers collect and use your data shows that disloyalty can trigger the biggest rewards.<br /><br />For more video content from the Financial Times, visit http://www.FT.com/video<br /><br /><br />Twitter https://twitter.com/ftvideo<br />Facebook https://www.facebook.com/financialtimes
