I found this gem: 7 Confessions Of An Apple Macintosh Specialist which is interesting partly because of how they fix iPods (they don't), but more for their religious policy of getting your email at checkout. It's all about the Net Promoter Score. Here's the detail:
2. Why we will ask you for your e-mail at checkout. This is for two reasons. One, we will send your receipt to your email, and two there is a survey at the bottom of the email. This leads to the store being ranked on what is called detractors and promoters. The company takes an average from the surveys and ranks us. 10-9 is a promoter, 8-7 is a "passive" and 6 below is a detractor. Which leads to the next confession.1. If you fill out the survey and rank us 6 or lower, a manager will call you the same day or the next, corporate policy. They usually will ask why you had a bad experience, and offer to make it better, usually by discounting something or another for you. These are directly related to the salesperson who checked you out, so we get our asses reamed when we make a detractor. Also, If you complain to a manager, nothing usually gets done, it goes in one ear and out the other. Buy something very small, have them email your receipt, and fill out the survey. The management will wait on you hand and foot. Oh, and return the product.OK, so slightly cynical at the end, but evidence of the good practice Apple have to improved customer relations. Customer Satisfaction runs through the company at all levels. Probably why their NPS is so high.And a great example of how you can use Net Promoter Score in retail.