Cost Affective Local Marketing - Does It Exist?

There is a whole variety of local marketing opportunities from putting a poster in a local shop, to radio, printed press and of course Google, Bing and Yahoo local, but what works best, in other words what is the most cost effective way of promoting a business in its local area. There are two main factors firstly the type of business and secondly its location. Local marketing is a very broad term that means advertising in your locality now this could refer to a town, district or county, but local is also measured differently upon the type of business for example a local shop would be with 1/2 a mile where as a local restaurant would only be a mile or 2 away, and a local garden centre could be 5 miles away.