Walking past all the shiny new electronics to the help desk way at the back is enough of a sales tactic for them. there's a reason all Apple stores have that layout, they don't need to train their techs in sales as well.
Strasbourg's Apple store has two distinct "front" an d "back" entries and two distinct half-floors that communicate by a couple of steps and are separated by a big wall, respectively for the sales side and the support side. Note that the "back" one isn't really "back", it's more like opening towards a mall instead of outside.
