An interesting post elsewhere, via Instapundit.

The consumer in me says Wal-Mart sucks anyway, for a variety of reasons (not the least of which being not paying their employees enough to live off even Wal-Mart ware). The marketer in me sees this and wonders about demographics, geography, and the types of products that are involved.

There is also shopper history, as in whether the people who seem to be upscaling from Wal-Mart ever shopped at Wal-Mart to begin with. An unlikely, but haunting, idea is that maybe the income class of people who can’t afford to shop anywhere but Wal-Mart are making less money and those who can afford to not shop at Wal-Mart are making more. In other words, could it be that the financial divide in this country may be growing with Wal-Mart falling at least partly into the rift? I have nothing to support this, merely thinking outside of the box.