The article is based around the results of a test undertaken by Greenlight. They took 1,000 keywords and recorded the top 100 ranking sites for those keywords 10-15 times over the course of a single 24 hour period. This resulted in a record of approximately 1,000,000 URLs, and the ranking fluctuations they had experienced within the space of a single day (starting and finishing the test in the evening).
The article reveals insights into: