Google virtually controls the search engine optimization (SEO) world today. For many people, when they want information they “google” it – a sure indication that the name has become synonymous with SEO. (In a previous existence, in the UK, I used the verb “hoove” for vacuuming – “Hoover” being the origin of the verb!)  Most googlers, though, are unaware of Google‘s virtual domination of the online advertising industry: according to Wikipedia,  Google‘s advertising revenue in 2010 was $28 billion.

Google‘s big challenger for advertising revenue is Facebook, with over 750 million members worldwide, and more advertising revenue in the U.S. than Google. Their big advantage over Google is that, rather than targeting people based on their searches, Facebook can use their members’ demographics and social behavior to target  advertising. Enter Google Plus and the +1 box.

You see, a lot of Facebook’s strength comes from the use of the “Like” button. Every time you “like” something you’re telling Facebook a little bit more about your interests: have you noticed how this affects the ads that you see? Advertisers can select a fairly narrow cross section of their global audience using Facebook‘s demographics and “like” information, thereby getting a much bigger bang for the advertising buck.

So Google decided it was time to play the social website game, and out came Google Plus, released in May to about 10 million users. So far, it’s still a newcomer, but it won’t be long before we feel the impact. Google Plus has the potential to outstrip Facebook before too long, combining the social nature of Facebook with the SEO capability of Google.

Like Facebook, Google Plus lets you build a profile, put in your personal details, join a community, and connect with friends. And, with the +1 button performing the same functions as Facebook‘s “Like” button, Plussers can approve websites, ideas and products, disseminating their likes to their network (and Google, of course.)

The interesting difference between “+1”-ing and “Like”ing is that with +1 Google can tailor your search results to your +1s. Quite what the effect of that is remains to be seen, but you can bet that it will help Google‘s advertising revenues build even more. Google Plus could signal the end of Facebook‘s social domination, not because it adds much to the social concept, but because of the advertising benefits.

Google, of course, has always used factors such as location and past search history to sense whether a particular search result is likely to meet what you’re looking for. The difference now is that they have access to your likes and also to your circles of friends’ likes. In general, people who flock together on social sites have similar interests: hence Google knows from what your circles like what you might like. Powerful stuff for advertisers!

So what does it mean for us as marketers? I guess the first question is one of timing: when are we likely to see this taking effect? My best guess is in time for the Christmas holiday shopping this year (that’s what I would do in Google‘s place.)

Given that, we only have a couple of months to put together a strategy to take advantage of this new opportunity. What to do will depend, of course, on the type of business you’re in and what your products are, but it seems there is something here for all of us to think about.

Let me know your ideas, and let’s see if we can make this the best Christmas season yet.