This message was on my Kroger receipt last night
(I do have Kroger Plus Card and I live in WVa)

You are invited to participate in a special promotion just for your home. Spend $400+ from 11/19/09 - 12/12/09 and earn one 10% off total order from 12/27/2009 through 1/09/2010. Purchases exclude RX, Fuel, alcohol, tobacco, gift cards and office services. Check your receipt for updates

I know they did something like this last year but I believe it was 20% off though.
The cashier said everyone had different amounts they had to spend so maybe everyone has different discounts too. Spending 400 in an month will be a breeze for me.. 3 kids with neverending hunger, 2 dogs with the same and a skinny husband who can eat the whole contents of fridge with out gaining a pound (grrr)