A Google Maps listing only gets lots of hits if there are lots of people making location specific searches for your product or service. For some products and services there is not a volume of local searches, for example for window shutters there are very small number of searches for say shutters Surrey but a greater number for Cedarwood Shutters.

A Google Maps listing is a very good thing to have as will assist you being found locally, but its effectiveness will depend on your industry and the number of local searches.