The waiter looks at me as if I’m an alien. I really don’t have one I reassure him. “No voucher sir? I’m sure you can find one on your phone? Or the lady over there has a spare one.”

Yep. I’ve just had to do the walk of shame – leaving a Pizza Express having paid the full price, the only diner paying the bill without a discount voucher. IPM data just released reveals that retailer coupons in the UK grew by 78 million redemptions from last year to a staggering 170 million redemptions. And the biggest growth of course is digital, growing 230% year on year. It’s part of how we shop now, part of the restaurant experience.

But for all the vouchers being redeemed, the digital vouchering mechanic just isn’t working well in supermarkets. The issue is proof of purchase and stopping the “double dippers” – those shoppers that reuse their vouchers. The proof of purchase bit is doable but only through unique codes on packs, which means plugging into the supply chain and manufacturing process, and as marketers know, that means weeks and months to set up.

Using barcodes or even the camera functionality of our phones doesn’t help either, there’s no proof you bought that box of cereal unless it’s printed on the inside. And stopping the “double dippers” means removing the voucher from the smartphone or tablet once it’s scanned.

The double dipper conundrum comes from the fact that the supermarket sales systems just don’t link up well with our phones and those of suppliers or brands to allow the voucher, once used to be removed from the phone/tablet and for the redemptions to be recorded by supplier and grocer.

Shopitize is the only app I’ve come across so far that starts to battle the proof of purchase piece, but even that, taking pictures of your receipt then uploading and waiting for approval feels like too many hoops to jump through.

Voucher codes work well for online shopping but as self-scanning with phone trials begin to kick off (well done Sainsbury’s!) the grocery industry needs to get moving to a common voucher platform for in-store. If you can have your boarding card for a flight scanned straight onto and from your phone, a mobile voucher for a free Coke really shouldn’t be that tough should it?

Let’s get this vouchering thing sorted out, the walk of shame really isn’t much fun.

http://marslondonblog.co.uk/2012/11/26/the-walk-of-shame/