It's probably good for bookstore scenario but for asking people about maps requires that there must be (helpful) people around with good knowledge of the area.

It's probably good for bookstore scenario but for asking people about maps requires that there must be (helpful) people around with good knowledge of the area. And for friend's location, calling requires input from someone else (which makes it slower, costlier, and imagine getting call from your friend asking for your location every x minutes [you can only do that so many times without "crossing the line"])