Google is a huge growing company, currently it has 20+ thousand employees in more than 30 countries. Out of the 20,000+ employees, less than 200 employees are really important. Like all companies, there are core departments and there is the rest. It's the quality control department that decides what to do with all the websites, what to display and how to rank the results when it comes to search.
Every year, Google's quality control team does one or two “clinics.” A clinic is a public session where Google's quality control analyse and explain what's good or bad in various websites. Many people, like consultants, try to do the equivalent to Google clinics, but… they don't know! The consultants guess. Sometimes they are correct, but more often than not they are often wrong! The only people that “know” are the quality control people at Google.
Last year, Google did a clinic in London, UK. Here are some of the “important” points: