Most retailers pay a great deal of attention to the merchandising, layout, and design of their stores. However, many fail to consider the comfort level of their customers.
Somethig as simple as temperature can affect a person's decision to buy from you or how long they spend in your store. And, we know that the longer someone spends in your store, the more likely they will increase the amount the spend.
I came across this article and thought you would enjoy it. http://www.stores.org/archives/2007/4/edit1.asp
The concepts may not be directly applicable to your type of retail store. However, with a little thought and brainstorming, I'm sure you can think of ways to use this information to improve the shopping experience for your customers.