Better selections and more knowledgeable help are two of the widely cited advantages that supermarkets have over mass stores. This is an interesting finding because it suggests a major opportunity for supermarkets to maintain their edge - and a major opportunity for mass stores to keep moving in on supermarkets that don't maintain their assortment and knowledge edge.
* "A new Super Wal-Mart just opened in our area and I shopped there before the announced grand opening - so shelves were full but there were no big crowds. I only shopped the grocery side of the store, whi