Will 2008 be the breakout year that some of Google (NASDAQ: GOOG)'s products and services besides search-targeted ads are able to start contributing revenue to the company's bottom line? Pundits will be watching for that, as will Google shareholders, who are mostly large fans of the stock, but reserved in the "eggs in one basket" approach Google still has when it comes to revenue diversification.

Are Google's products like Gmail, Docs and Spreadsheets, and Calendar holding up their fair share? Gmail is the only product that includes advertising, and Google is careful not to say how much revenue it receives from customers clicking on ads within Gmail. How about Google Base? It's just an entry point into Google Search. Google Trends? Google Book Search? Google Page Creator? Google Notebook? All of these nifty products are -- for now -- free of charge to use, but don't have any kind of ads, which could directly produce revenue.

Google's hope for 2008 revenue beyond search advertising rests in many areas, from YouTube advertising to generating an actual income from subscribers to its Google Docs and Spreadsheets product for large installations (universities, companies, small businesses, etc.) that would prefer not to spend a small fortune on Microsoft (NASDAQ: MSFT) Office, and who also want web-based portability for their documents anywhere there is a web-connected computer.

Does the web search leader have plans to diversify revenue even further than these two examples? Surely -- but gleaning that information from the company will be met with competitive-advantage silence for now.