It's a great day to be a Google (GOOGL 0.55%) investor. Shares are hitting all-time highs today, up as much as 13% following the release of Google's third-quarter earnings yesterday afternoon.

Google's top-line revenue grew by 12%. Earnings grew by 35%, and the volume of clicks for search was up 25%. This helped to offset an 8% decrease in the average cost-per-click. Motley Fool analyst David Meier thinks beyond the great numbers, there's a hidden story here. There's a business ordinary investors aren't paying attention to, which just posted growth of 85%. In just a few years, it now accounts for 8% of overall revenue. Google is known primarily for search, but this growing segment shows that Google continues to find new ways to create value.

Shares have returned 40% year to date, and today have crossed the $1,000 mark. Despite this, David thinks Google is still a buy. He argues there's simply not a better cash-flow machine than Google.