If you have spent any amount of time in the link building world, you will note that it takes some serious time to really rally up and start gaining some momentum in the search engines and start to see things pick in terms of where you are ranking in the SERPs.
This is especially true with very competitive keyword phrases. Jumping from page three to page two, and from page two to page one can be very tough in a competitive niche - even when you are link building at a very high scale (however jumping from - say - page eleven to page eight is considerably easier).
Link building and Relationship management (sometimes public relations is a part of it) software is supposed to help you keep track of these relationships. With it, you are able to build a humungous database of contacts, and you are able to keep track of where all your links are coming from.
In an article I have previously written on this website, I describe the benefits of using a system like this. The particular software I was talking about in this case was called Buzzstream, and you can find that article here.