Personally, I often have to decide if I want to spend a flat $6 fee (often less) for shipping and shop in my bathrobe or get in the car, fight traffic, jockey for parking, stand in line, risk not finding what I want, etc. for the instant gratification of having it now.
Currently, my ‘06 Toyota costs 22.37 cents per mile to drive (gas, maintenance, repairs. Makes shopping online an option.