And if you think the WalMart greeter is pointless, think again. The Wal-Mart greeter was actually developed strategically to slow you down as you walk into the store. Most people miss the first 30 feet of walking into the store because they are simply moving too fast when they enter. The Wal-Mart greeter is there to slow you down and thus allowing for that 30 feet to be used to sell you stuff.
They had that at ASDA in the UK as well. I always felt quite disgusted by the idea that a company pays someone minimum wage to say "Welcome at our store, Sir". Like prostitution really when you think about it.