The launch of Google+ apps sends a powerful signal – the personalized web has begun. What this means is that the way information is structured and accessed will turn on the individual, or rather their personal profile which is a composite of all the data collected on the basis of what they have searched for and shared. What this means for brands and their marketing is enormous.

As the individual becomes the filter through which all information must pass, the onus for brands to be defined and social becomes acute. Here’s why.

Till now, search was outward facing. When you wanted to find something you entered its name and in most cases, relied on Google to provide a list of ranked links to that topic.But now search, and the way information is structured and accessed is becoming increasingly inward facing with the individual as the filter. That means when you visit a website the ads will reflect brands, topics or causes that you have demonstrated a past interest in through what you searched and shared. In short, your experience of the web is being built from the individual out, in circles as Valeria Maltioni rightly explains.

With this shift in informational structure and emphasis in mind, what happens to the undefined brand? How does a brand that either stands for nothing, or more commonly, several things at once, pass through the individual filter of the personalized web?

Brands reluctant to do the hard work of defining what they stand for and integrating that within their organization, or brands that mistakes social technology as an end in itself rather than as tools to connect people emotionally, run the very real risk of becoming invisible and obsolete. Put simply, brands must accept that they are no longer the destination. Their customer is. And as such, self-definition is a critical tools through which your brand, and its products and services, can reach it target audience.

If you doubt the importance of this shift, you need only look at how much competition there is for the potential customer’s attention these days and platforms (like SocialVibe) or strategies (like bonuses, rewards or coupons) that are used to command it.

Brands are facing a new competitive landscape in which self-definition, core values and purpose will increasingly define their ability to reach customers that only allow what is meaningful in their lives to pass through their filter.

At the 4A’s conference this year, Unilever CMO Keith Weed asserted that “the customers are in charge” of the conversation. The advent of Google+ and the emergence of the personalized web means this is more true than ever. Brands, and their advertising partners, must wake up to this challenge and define themselves with clarity, consistency and authenticity. Otherwise they just might find themselves shouting in a ghost town.

Do you believe the customer is increasingly in control? How do you think brands must respond to the personalized web?