A leaked Google "vision statement" has revealed the search giant's agonising over just how far to go in profiting from the vast array of data is holds on the world's Internet users.
The seven-page document seen by the Wall Street Journal, stamped 'Internal Confidential', was compiled in late 2008 by Aitan Weinberg, now a senior product manager for interest-based advertising at Google.
Guided by their founding principle "Don't Be Evil", the search giant's founders Sergey Brin and Larry Page have in the past tried to maintain the company's reputation as a benign titan.
But it the wake of a more cavalier approach to user privacy by rivals such as Facebook, the company has been tempted to make greater use of user data.
And for the moment, at least, it looks as if there's little to stop them. Last year, the US Federal Trade Commission ruled that the advertising market could continue to self-regulate, as long as firms disclosed what information they were collecting to users.
The potential of that exploitation is massive. Roughly 75 per cent of all Internet users - that's 943.8 million people - used Google's services in June, according to advertising analyst comScore.
Figures from market analyst The Diffusion Group put Google's online advertising revenue for 2009 at $23.7 billion, more than three times that of its nearest rival, Yahoo.
Among the ideas discussed in the document - filed under "wacky" - is a proposal for a user information marketplace:
"Google can build a data exchange/trading platform allowing data owners to transact with others directly, or openly sell their data to any bidders. These ideas span a range of safe and not so safe practices."
Others include precisely targeted, timely ads based on detailed info Google collects about a user's search habits:
"Relevant display ads (or test ads) could be delivered on [Google Content Network] to a user within 15-60 minutes of a given search, whereby the timeliness of the ad would presumably increase its relevancy to the user."
An anonymous source who talked to the WSJ called the paper a "brainstorming document", and said that many of the ideas contained within it were "complete non-starters" - but a number of its suggestions have gradually begun to trickle through to implementation.
Among them is a new tracking code introduced last year that enables the search giant to track individual users across the Internet.
The move followed a stormy meeting at Google's Mountain View headquarters that saw founders Page and Brin engaged in a shouting match.
"It was awkward," said one insider. "It was like watching your parents fight."
Users concerned about what ad information Google gathers from their search data can opt out here.
Another idea from the document that has reached the market is Google's new ad. exchange, which uses Google search data to target adverts at consumers on other web sites. Google takes a cut of each ad. sale.
At present, Google doesn't mix together the separate 'pots' of data it holds about individual users - so it doesn't use data collected from a person's Gmail account to serve targeted ads to that user elsewhere.
But all that could change. As personal information becomes the number one commodity on the Internet, Google is uniquely placed to dominate the market.
And with greater competition in the search engine market than at any time in the last decade, how long before the search giant exploits its advantage?