A test of using Google to power Yahoo! Web search has been successful, according to a report in The Wall Street Journal, and the test could lead to Yahoo! outsourcing its search advertising to Google on a larger scale. Google is able to more effectively monetize search than rival Yahoo!, and one analyst thinks the deal could add more than $1 billion per year to Yahoo!'s cash flow. However, regulators are likely to take a close look at any large-scale tie-up between these two market leaders, analysts say.