I think this site is a great idea for retail owners. As long as they sell to employees at a profit, this is a really good way of increasing their price discrimination.
Most of those people who are happy to pay full price won't bother using this site anyway. Those that aren't, but are willing to pay the discounted rate will become extra sales the company would not have otherwise had.
[Edit: I don't believe that employees should do this behind their employers' backs, just that it's probably a good idea for the employers to let them.]
Only if they know the site exists, and are willing to bother themselves fiddling with it. The dollar rich are often time poor, so will be willing to pay full price to save hassle -- after all, they don't collect coupons (for example).
No, the way price discrimination works is that you set up hurdles that are expensive for someone who makes $80/hour and cheap for someone who makes $8/hour, so you get business from both. If this site reduces the cost of getting a discount, it weakens their price discrimination power.
Fiddling with a website and trying to arrange a transaction with one of these insiders is expensive for someone who earns $80 an hour. They're time poor generally, and they don't want to waste what little they've got.
Most of those people who are happy to pay full price won't bother using this site anyway. Those that aren't, but are willing to pay the discounted rate will become extra sales the company would not have otherwise had.
http://en.wikipedia.org/wiki/Price_discrimination
[Edit: I don't believe that employees should do this behind their employers' backs, just that it's probably a good idea for the employers to let them.]