Certainly the rising price of gas is having some effect, but you can't blame all of it on that. Other factors are still too-high unemployment, and conversely some people rehired or making enough now that they prefer to shop at higher quality places. I think also the reality is that Wal-Mart's concept has simply gone stale. They have plenty of competition for the warehouse gimmick, plus some higher end specialty retailers have modified their pricing structure to be more competitive with the discount stores. Best Buy comes to mind.