I have been using Link Emperor to build my website ranking. The big search engines are always changing, or at least threatening to change, their algorithms. Backlinks to a website are a great way to improve a rank in search engine results. The backlinks are simply websites that have links to other websites. The quality of the websites providing the backlinks is taken into consideration by the search engine. If a website that is listing backlinks is deemed to be a high quality site, then the backlinks pay off in moving up the websites listed in those links in the search engine results.
A major issue is losing the effectiveness of all the work put into building the links overnight if a search engine algorithm changes.