What is Concentration Approach for selecting target markets?

Concentration Approach:

As an organization directs its marketing efforts in the direction of a single market segment by a single marketing mix, this is using a concentration approach. This permits a company to focus all its marketing efforts onto a single segment. A main restriction of the concentration approach is that, when a company depends onto a single market segment for its entire sale and which segment’s demand for the product declines, sales and profits of the company will also decline.