With Facebook announcing a major new messaging system (codenamed Project Titan) and Google snapping up acquisitions all over the place (83 so far) – what is the fundamental difference between these two giants of cyberspace?

The answer lies in the kind of data that they both deal in.

Facebook lets you tell the world all about you – what you ‘like’ about culture, companies and people. It is data that you want to give away so that you can show other people just how much of an individual you are.

Google, on the other hand, is a lot more personal than that. It is about what you really get up to when it is just you and the computer. It stores data about everything from your embarrassing rash to your sexual desires.

As Sebastian Anthony puts it:

‘Facebook knows who we want to be, while Google knows who we actually are.’

We could see this as Facebook being all about your public self, whilst Google is all about your private self.

Of course, the bottom line for the companies involved is all about how this fundamental difference affects revenue. Facebook advertises to your public self, and Google advertises to your private self.

The question now is whether Project Titan will change this fundamental difference by reading your Facebook emails and targeting adverts (something which Google already do).

This would be an advertising model based on both your private and public identities. Priceless to marketers, but something that I find unsettling.