That's not to say that keywords, backlinks and proper search engine friendly design will cease to matter, they probably always will. The problem is that keywords, backlinks and web design are easily manipulated. So in order to survive the deluge of spam and stay on top of the black-hats, Google at al are turning to other ranking factors to assess a web page's credibility and trustworthiness.

What are they?

According to SEOMoz the face of search will change in 5 key ways. Each of these factors is going to gain increasing importance over the coming months and years.

1.    Analysis of a site/ page's perceived value to users.

2.    Social signals at page level

3.    Social signals at domain level

4.    Usage data

5.    Content usability

What can we learn from this? Well, Google is clearly aiming to downgrade the importance of inbound links, aiming to replace them with a more sophisticated, user-centred credibility metric. Instead of anchor text backlinks we're likely to see social activity - ReTweets, Facebook likes, Google's own +1 button - gradually come to the fore.

What does the mean for the marketer? Don't stop building links and optimising your page content for target keywords but start thinking a lot more clearly about your social media plan. Get a presence and get active, join in with the community, share and contribute and engage with the stakeholders in your industry.

There's immense value to doing this beyond SEO but if the SEOMoz annual Ranking Factor report is anything to go by social signals will be a key determinant of search engine success in the coming years.