Street hawkers, fruits/vegetable vendors by the roadside - these are pretty common sights in India. I was riding with my wife this morning. At a bend, we noticed a couple of fruit vendors - one was selling lichees and the other, mangoes. We passed the bend and had gone further 20-25 meters when Arti tugged at my shirt and said, "The lichees look good. Let's buy some." We took a u-turn and bought some lichees. And then, as we were about to resume our ride, we bought mangoes as well.
Fruits are very often sold this way - one vendor selling one thing. The sight of one thing stocked in a huge quantity leaves quite an impact. Not only does is it visually attractive, but also makes one think that the fruits are of good quality, fresh, and perhaps, with good taste too. It whets one's appetite. If a good mood coincides with the sight, one ends up buying. Recall your own experiences and you'll notice that the same would occur less often if one vendor has stocked many types of fruits.
What's the import? Focus. Yes, focus on one thing, you'll most likely sell more.
Am a fruit lover. Therefore, to an extent this post is personal. But this small little commonplace occurrence by the street-side, I feel, includes a lesson.