I found this on a travel site-
*Street vendors - Once you've been here a while you get better at handling them, avoiding eye contact, not falling into traps like agreeing to buy something from them 'later', just to get rid of them. They will remember you, and if for example they see you with a pair of sunglasses bought from another vendor, they will sadly remind you of your earlier 'promise' to buy from them 'later.' They really look heartbroken that you've betrayed them for a rival vendor!
Sound familiar??
It was for VIETNAM.
Well, at least I'll feel at home. LOL