We like Facebook, and we’re not alone. It is currently the most visited site in the U.S. and boasts 400-plus million worldwide users. This week, Facebook took a big step towards becoming even more ubiquitous. The changes are a little tricky to understand, so here's an attempt to summarize.

Facebook Profile Goes With You
First a quick explanation of the impact: With these changes, any website is now able to display content and products informed by a user’s Facebook profile – information like current city, likes, interests, etc. To clarify, this all happens without requiring the user to sign in on that website or provide it with any personal information. It’s simply a matter of the user being logged into Facebook, which is the first thing many users do when they go online.

Washington Post shows recent activity of friends and Facebook community at large.

“Like”
The other big change is quite simple - a "Like" button that is already appearing all across the Web. With a click of this humble button, users share a link with their Facebook friends. But alas, so much more is happening behind the scenes: a link is added to the user's profile, publishing to the user's News Feed is allowed, the link is included in search results on Facebook, and analytics recorded through Facebook’s revamped Insights product.

Companies around the world – including The New York Times, Washington Post, and Levi’s - have already launched some of these features, joining Facebook “to make the web a more social place.”

Levi’s ecommerce site is built around Facebook’s “Like” plug-in, claiming “Like-minded shopping starts here.”

Summary of Changes
Facebook has organized its new features into three categories: Social Plug-ins, Open Graph, and Graph API.


Social Plug-ins

Like Levi’s, CNN has made a big commitment to the “Like” feature. They’ve renamed it “Recommend,” however. NewPulse is a new section of CNN.com devoted to scoring stories by Facebook shares.

Open Graph
With the old Facebook, users are connected to people they know, as well as public figures, services and products they like. With the new Facebook, websites and apps will be able to share this information with each other.

Facebook has partnerships with Microsoft Docs, Yelp and Pandora for this initial launch of cross-website information exchange. Here’s an example of how an exchange might unfold. A user connects to Yelp.com while logged into Facebook. Yelp then has access to any information he has made publicly available about his favorite foods and bands and will tailor recommendations. Yelp could also pull information about his favorite music from data that Pandora added to the graph when he favorited a song on its site.

Graph API
Facebook has made it very easy for developers to implement these new features. For example, developers only need to drop one line of HTML into a website to include one of the social plugins. You don't even have to be a developer to make your own “Like” button. Facebook has provided a simple wizard to generate the code. Fill-out a few form fields, and it's just a matter of copy-and-paste to get the button onto a site.

On its Developer Blog, Facebook describes how the Graph API is more powerful than before, “We've enabled a search feature which lets you search over objects like people and events, and over the stream — both public stream updates and personalized ones for your users. In addition, the graph is ever-changing, so we're launching real-time updates to let you subscribe to updates to user data.”

Privacy
Since Wednesday’s announcement, Facebook users have expressed concern about privacy and the default opt-in settings.

Said one commenter on Mashable.com: “On one hand, having your web experience customized to your tastes, interests and relationships is appealing. On the other, it’s going to be hard to keep track of all of the personal data you’ll be publishing to the graph for all to see — and there might be some opportunities for abuse by less scrupulous companies.”

Conclusion

In general, I “Like.” As an avid Facebook user, I discover most of my news and current events via Facebook. It’s how I discovered that Michael Jackson had died or that my cousin had successfully undergone a heart transplant. I gain a lot from my community of friends, and I try to give back. These new features allow us to connect with each other all over the web, not just within the domain of Facebook.com.

Basically, my friends’ searching and browsing habits have the potential to become a really smart recommendation engine. I get to see the stories and products that my trusted friends like, within the original context of CNN, Time Magazine, Washington Post, etc.

Many people are disgruntled that Facebook opts you into these features by default, and to opt out is a multi-step, fairly confusing process. I heard from several people today that they’re likely to be more careful about who they friend and may even down-size their community. I think that’s smart.

Examples:
CNN
Levi's
Washington Post
Facebook Platform Showcase

Learn More
For more detail check these articles. They talk more about what you can do and what is coming. The Agency Spy is a good summary. Mashable and Wired go into more detail. Mashable seems to have the best all-around coverage.

Agency Spy
Facebook Open Graph: Everything We Know So Far

Mashable
Facebook Open Graph
Facebook Makes Major Announcements at F8
Facebook Open Graph: What it Means for Privacy

Wired
Facebook Adopts Open Standard for User Logins

Facebook Developer Blog
The Next Evolution of Facebook Platform