Just a few months ago, Facebook announced its Open Graph and social plugins. By almost any measure, this can be considered one of the most successful launches in history. Within 24 hours Facebook had served 1 billion "Likes." Within one week, Facebook Like had been implemented on 50,000 websites. After only six weeks, more than 100,000 sites had implemented Facebook Like. Wow.

With Like, Facebook is set to challenge Google. Like is rapidly becoming an index of content on the web, where the index is built based on mass popularity as opposed to an arbitrary Google algorithm. The impact of this cannot be overstated.

Facebook is the number one website in the world by page views and already refers more than twice the traffic to news and media sites than Google. Web users spend more time on Facebook than all the time spent on Google, Yahoo!, YouTube, Microsoft/Bing, Wikipedia and Amazon combined.

If Facebook is the next Google, then Facebook’s social plugins are your SEO tool kit for optimizing social commerce. Of these, Facebook Like is, by far, the most important — and also the easiest to implement with just one line of HTML.

Given the impact of Facebook’s social plugins, we decided to run an internet survey of e-marketers to discover how marketing plans have changed. 476 e-marketers participated in the SeeWhy Research internet poll on Tuesday, June 15th.

It’s taken only a matter of a few weeks for e-marketers to act on this: Almost 7 out of 10 of the e-marketers surveyed have already implemented Facebook Like or plan to implement it.

Since it is just as easy to unlike content, e-marketers need to be responsible about how they use "Like." Sending a stream of irrelevant posts to your new Fan’s wall will result in a very quick "Unlike."

Next in priority for e-marketers’ implementations is Facebook "Login with Faces" (which replaces Facebook Connect). Facebook Login enables visitors to log into their Facebook accounts on e-commerce websites with their Facebook credentials rather than creating site-specific accounts. It’s so easy to do that Facebook reports that site visitors are three times more likely to use Login than create a specific website account.

Fifteen percent of e-marketers surveyed had already implemented Facebook Login, with a further eighteen percent planning to do so. That one third of e-marketers plan (or already offer) Facebook Login on their websites is significant. One of the reasons is that a user signing in with Facebook Login is consenting to share their personal details with the website. This opt-in is very valuable, and e-marketers know this.

Once opted in, on-site activity can be tracked and associated with an identity, and following a session, the individual fan can be remarketed to via email. This has long been high up the wish list: to be able to market to Facebook visitors with special offers and promotions. This new capability will have to be used responsibly since the opt-in permission is controlled by the Fan in his/her account settings; so it’s easy to un-login, although not as intuitive as many of the more vocal Facebook privacy advocates would like.

Charles Nicholls is founder and chief strategy officer for the consultancy SeeWhy.