There has been research in the past supporting the notion that certain music does strengthen peoples' purchasing tendencies. I don't know about recent evidence. Many of the ways that dept. stores are laid out comes from research on consumers--the things that are clustered around the check-out counter for "impulse buys," the way the display gondolas are arranged, what's displayed on the gondola end-caps, etc.--the whole environment. I formerly ran several companies which did dept. store interiors and store fixtures, so I used to live and breathe this stuff. I can't even go into a store without studying how it's put together and presented.