Google is unlike many other companies ranging from the way they operate to the innovative ideas for the web. That is why it is not unexpected for them to run differently in regards to purchasing shares and the reasoning as to why they went public. Instead of going public for more money, which they had enough of they went public for some of their investors to realize their gains.
On August 19th 2004, Google goes public with shares prices at $85 a share. Google uses a unique online auction format to allow investors to purchase shares. They used this unique auction format instead of the book building method because it made it more international than solely U.S based.
Even though Google did go public, it only offered about 19,605,052 of its shares, and this only accumulated to around 7% of the company.