In the early days of the Internet when Google was young and Google's Dance were setting the pace. Once a month Google would perform a re-indexation, which was viewed as a mystery. This resulted in overpatching in SE results which were reflected in the Google Toolbar.
Usually, after about 2-3 weeks after re-indexation the forum discussions began to die out in expectation of the next re-indexing. All SEO webmasters were waiting for new Google Dance. But Google matured and at re-indexing became more frequent. This led up to the current status: Search results differ from day to day.
However, this made the SEO engineer's job so complicated it was virtually impossible to remember how the site appeared in past results and how competitors reacted.
For these reasons we need to create an on-line resource which duplicates how these searches were made in the past. This led us to create the new service
SerpArchive.org which will aid in analyzing the changes in SE results. This will result in better, more accurate results in the future.
We are open for your opinion, questions or suggestions.