So if you conduct a search for Saturn, in the science directory of Yahoo, the results should not include Saturn the automobile. Searching within a directory usually yields less results that are better focused. Since Yahoo uses real people to sort sites into directories it is difficult for them to include every site, so Yahoo uses the search engine Google to search outside of its directories. Search services make money by selling advertisement space or being paid by companies to list their site in the query results. It is becoming popular practice for search sites to provide free services, such as free email, at their sites to attract more users.
More users equal more revenue from advertising sales.
As a result, some search sites are not focusing on providing the best search technology anymore. Perhaps, this is why Google is receiving praise. They do not provide free email or other perks to their visitors and they do not have slow loading banner advertisements. Their site has a clean and simple layout, without providing distractions to the task on hand. They make money by listing companies in the query results.