Every-time we re-crawl your campaign ( that is weekly normally ) we record a variety of important data points such as live/lost links, referring domains, nofollow links, unnatural links etc. All these data points allow you to understand the evolution of the analyzed site.
Other useful articles:
http://cognitiveseo.com/blog/1385/backlink-analysis-tool-link-analyzer-intelligence/#5
http://cognitiveseo.com/blog/1385/backlink-analysis-tool-link-analyzer-intelligence/#15