Google runs different search engines around the world. Most of the search engines are organized along country lines for the following reasons:
- Language Issues: Different countries use different languages. When people ask for a search result, they prefer to see everything in the language of their country.
- Distributed Computing: Google runs essentially the largest supercomputer in the world. It is so large that it can't be run in one place. Google's computer system is naturally distributed over many server farms spread all over the world.
- Speed of Response: To minimize traffic flow over the global Google network, Google tries to match search results with the nearest Google search engine.
- Regulation: Google has a need to meet many different government rules and regulations regarding content, access and privacy. This is best served by using local country search engines.
- Local Search: Well over 80% of all Google searches are for local search results. For example, someone looking for a pizza place in Sydney, Australia wants to see results for local pizza restaurants, not the results for pizza places in Sydney, Canada.
This last point is worth highlighting because it introduces a significant bias in Google ancestral search results. It works as follows: even though we live in a global world, most traffic across the internet still remains within the boundaries of a single country. For example, most of the emails you send are probably to people who live in the same country and most of the websites you visit are probably in your country.
You can actually see the localization of global internet traffic in the diagram below. It visually shows traffic from Facebook, the popular social networking website. A single line in the diagram represents the social link between thousands of people. The diagram is the cumulation of thousands of these lines showing the social interaction of hundreds of millions of people.

Global traffic on the Facebook network.
Notice that for almost every country in the world, the vast majority of linkage is within the country.
Another important consideration when searching for ancestral records is to recognize that Google is a general search engine designed to handle a variety of search requests. It is not optimized for genealogy searches (for that, use the genealogy search engine).
