Whose Bag Is It Anyway?

Last weekend, Sainsbury's supermarkets gave away the reusable bags they normally charge for in the hope of encouraging customers to reduce their use of plastic bags. Today, I noticed a woman using them to carry her shopping from one of their rivals.

I wondered how many other shoppers noticed and thought better of Sainsbury's as a result? I wondered if the rival's staff noticed and thought about doing something similarly positive? Coincidentally, (courtesy of today's passiveaggressivenotes), I wonder why anyone would think this would be an appropriate response and why it's the stance being taken in so many industries?



Addendum: To clarify - do you see a customer advertising the competition or do you see a customer?