Fast Company says:
The Swedish retail giant [Ikea] encourages customers to use fewer bags by charging shoppers 5 cents for each disposable bag they take. (Ikea gives the nickel to American Forests, a nonprofit.) The policy, in effect since mid-March, has already cut bag consumption in the United States by more than 50%, far more than executives had expected… In the United Kingdom, the policy, which started in June 2006, cut bag use by 95%.
Customer behavior modulation through price changes, especially by adding a nominal fee for what used to be “free” is a well known retail strategy. The fee is really a vehicle for highlighting a specific usage pattern.
For example, travelers often leave behind hotel bathrooms in a mess: water splashes all over the place, dirty towels thrown about, toiletries scattered by the sink, toilet paper on the floor, etc. There’s no price incentive to keep it clean, and there’s no penalty for behaving badly. If hotels were to charge, say, a $5 fee for cleaning up the mess, I’m sure most customers would likely start behaving more like they do at home.
Out of sight, out of mind. The fee is the price of focus.
Therein lies a lesson for us designers.