Let the customer show their eco-cred without having to make another purchase.

For a lot of people, part of the appeal of doing environmental good is to actually "be-seen" to be doing the right thing.  Whatever the reason people crave that recognition (it may be to boost their esteem or to promote their eco-choices), it is powerful stuff.

This idea aims to boost the promotional value of reusing a drink receptacle, without the need for a customer to purchase a special new mug - and to help the customer increase their eco-credentials (and therefore the recognition of their peers and community) with every purchase.

The trouble with a lot of reward schemes is that they are invisible: the mechanisms for reward are hidden away in people's wallets or cupboards and the scheme itself needs constant promotion.  This one is visible and promotes itself.

The device:
a rubber band (similar in size/materials to those charity wrist bands) with a small bar-code attachment.  This is a BAND OF HONOR and is worn with pride on any coffee mug to clearly indicate to the world at large that the holder of the band is a GOOD CITIZEN with environmental intent. 

How it works:
A new customer buys (for a fee that is donated to an environmental cause) a Band of Honor with their coffee purchase.  It fits snugly around their coffee cup.  This first band is white in color.  The barcode is scanned and is recorded in the database that it has been used one time and may also record the patron's name and drink-of-choice.  The customer is told that each subsequent time they use that BAND on their own mug, they will receive (eg) 5% off their drink purchase. 
Because the BAND OF HONOR is flexible, it can be used on any mug or cup.  The customer can swap it from their car-mug to their walking-cup, from their home mug to their office glass, and wear it around their wrist (if they choose) when they are currently "between-cups".  If they buy an exciting new Starbucks mug, they can simply swap their band over to the new mug.

Increasing rewards:
Each time the customer reuses a mug with their BAND OF HONOR attached, it is scanned and the re-use recorded.  As the customer reaches a certain level of re-use (say, 20 times), their white BAND OF HONOR is replaced with a blue one and it is then worth (say) 7% off their drinks purchases.  Other patrons seeing a blue BAND OF HONOR know that the holder is worthy of their respect and admiration.

When the patron has had their BAND OF HONOR scanned 50 times (and reaping the rewards of discounted drinks, fame, and shorter ordering times as the staff only have to scan the code if the holder simply wants their 'usual') it is replaced with a green BAND.  This green one (along with upping the discount given) says to the world that its bearer is committed to ecological goodness.  The customer walks through the streets with this green BAND clearly visible on their mug.   

Then they get wise.  They start lending their BAND to their co-workers so that they too get cheaper drinks and so that the BAND can faster get upgraded to the next color.  (incidentally, this way of "cheating the system" actually promotes even more environmental goodness as it means that even more cups get re-used).

At 100 uses the customer swaps their faithful old green BAND for a gold BAND OF HONOR.  The rewards increase.  People on the street point it out to their friends ("look, that girl's got a GOLD one!").  When waiting in line at Starbucks with their gold BAND, the possessor hears other patrons ask the staff how they too can get a gold BAND.  ...and so the concept promotes itself.

The best bit: 
Any mug can go gold.  Even you.


Notes:
The colors and levels of reward mentioned here are examples only.  This could be a three-tier or ten-tier system with rewards that vary from percentage discounts to free products at certain levels.  The real advantages are :

• no new manufacturing techniques required
• re-using ANY cup/mug/glass qualifies and the band can be swapped from one cup to another so that the customer can use it for different size drink purchases or to move it to a new cup when their old favorite one breaks etc
  
• It's much easier to remember to take your band to the store than to remember to take a rewards card, because it is attached to your favorite cup (and can be worn on a wrist or easily stashed in a pocket if the customer is "between mugs"
  
• bands are re-used when the user upgrades to a new color (old band given to new participant)
• Potential for user to be recognized by their peers for their level of participation and therefore gain status credentials.  Social cache!
  
• Potential (through barcodes) to track scheme participation rates, favorite purchases of eco-friendly consumers, to offer speedier purchasing systems for participants who wish to purchase their usual drink (ie barcode has already recorded the owner's name and drink preference)