Applications and websites are like brands--each has its own particular reason for being. Build products and services around that singular reason, and consumers are more likely to understand, accept and adopt those new features. However, if a software package, site or brand attempts to expand in ways that violate their one essential purpose, consumers can become confused and reject the new (or even the core) offering.

Cosmopolitan Magazine Yogurt, Smith and Wesson Mountain Bikes, Walmart luxury goods, and Barbie clothing and accessories for adults--all of these brand extensions (must have) seemed like good ideas at one time but failed. Facebook is now embarking on its own brand and functional expansion, and it will be interesting to see what happens as the social network pushes beyond its traditional sandbox.

From the start, Mark Zuckerberg has had a clear vision of what Facebook is and is not. The social network is designed to be the online place for your existing, offline relationships. Zuckerberg once said, "we're not trying to build a community — we're not trying to make new connections."

This focus on facilitating real world relationships versus new connections is evident in everything Facebook does. Facebook's commitment to being a place for real friendships explains the social network's limits on the number of friends one can collect, the way groups were designed to degrade if they became too large and the way friends could add one another to groups without permission. It is also is why every Facebook relationship is required to be reciprocal--both parties must consent before a connection is made.

Facebook seemed content to let Twitter be the social tool for amassing influence and thousands of loose connections while Facebook focused on those dozens or few hundreds of firm and meaningful relationships we value in real life. But with the entrance of Google+ into the social networking world, Facebook seems to be innovating rapidly and, perhaps, giving up its commitment to real relationships.

Today, Facebook made a significant change to the way connections are created. People can still choose to "friend" you, which requires you to approve the connection in order to establish the relationship, but now users can also activate a new "Subscribe" button for their profiles. This Twitter-like feature allows people to subscribe to an individual's public posts while excluding their private posts. For the first time, you can follow a person's public Facebook posts without reciprocity.  (I've added the subscriber feature to my profile, and you can learn more and add this button to your profile on the Facebook Subscriptions page.)

Third parties have attempted to launch apps that push and pull Facebook away from its core mission of enhancing real world relationships. For example, in June Monster launched BeKnown, a professional networking application for Facebook. The application earns just 1.4 million active users, a fraction of the 82 million monthly users claimed by LinkedIn.  Perhaps the low participation is due to flaws with the application, but it's at least equally likely that people just don't wish to make professional connections with bosses, vendors, suppliers and peers within the same network where they post their kids' pictures and personal data. All that may change now that Facebook has deployed new tools furnishing you control over who sees your posts and for permitting others to subscribe and not just friend you.

Although others have tried to launch expansive networking tools on Facebook, today's news represents the first time I've noted Facebook itself taking a step away from its traditional foundation of firm, real, personal relationships. Is this a strategic move on their part to increase usage further? A reaction to Google+'s Circles? Or a mistake? Time will tell if this brand expansion will go the way of failed ideas like Bic Underwear (really!) or successful brand expansions like Arm & Hammer Toothpaste.

What do you think? Will Facebook be able to attract influencers who want to reach tens or hundreds of thousands with their public posts? Or will Facebook undermine its core mission?