I guess it depends on what the smell is?
THe smell of fresh popcorn is a HUGE plus!
it lingers in the subconcious and tells the patrons to come back for more!
on the other hand, the smell of old pop spills not cleaned up, mixed with others or the smell of unclean restrooms would be somewhat less effective at bringing MOST people back for more!
Dust? Hey isn't that why we keep the house lights dim? (Kidding)
as for spots, the only spots we have are Loganberry stains on the floor in the Aud. that won't come off, or salt stains on the carpet people track in from outside.