Building Quality backlinks is one of the most important factors in Search Engine Optimization.
It is not enough just to have a lot of backlinks, it is the Quality of backlinks along with the Quantity that help you rank better in Search Engines.
A backlink could be considered as a Quality Backlink if
1. The Theme of the backlinking website is the same as your website.
2. It links to your website with the keyword (keyphrase) that you are trying to optimize for.
This tools searches for websites of the theme you specify that contain keyphrases like "Add link", "Add site", "Add URL", "Add URL", "Submit URL", "Add Article" etc. Most of the results could be quality potential backlinks.
Importance of Backlinks
This article will explain to you what a backlink is, why they are important, and what you can do to help gain them while avoiding getting into trouble with the Search Engines.