There is much to be gained from the group of viewing customers. Despite the fact that they have indicated that they want to look around, a large part of them wants to be helped. Many sellers don't know enough about how to reach that group and how to make contact with it.
The way the customer walks through your store, his or her attitude, glance, viewing direction, expression, movement, all of this together gives you a feeling as a seller. Listen to that feeling and dare to act on it. In other words..
Observe and tune by listening non-verbally. Feel what their body language is telling you. If your feeling says 'yes', then that is the time to make contact. Timing is crucial. A little too late and the customer leaves, a little too early and the customer feels annoyed. Every customer situation is unique and has its own approach. Trust your gut and dare to make a lot of 'mistakes'.
What does it get you?
Lots of extra buyers and a full cash drawer!