Pure niceness. I always look for the "no pressure" vendors; the one in the back corner, the one pushed to the end of the row by the more aggressive vendors, the one who offers a pleasant greeting rather than trying to hard-sell. Hard sell and borderline intimidation will never get my business. I don't really need any more carvings and such but I'll support a vendor just because they are trying to make an honest living, and not hustling.