A new theory about the fate of Facebook is floating around the internet. Mike Elgan says it best: "Don't look now, but Facebook is quickly becoming the new Yahoo." And he doesn't mean that as a compliment. 

The backlash comes hot on the heels of Facebook announcing two new features: the Subscribe button and Smartlists. We pointed out at the time that the Subscribe button negates the need for Twitter--or at least Facebook would hope so. It's not dissimilar to Yahoo launching its own social network, Mash, at the same time that Facebook was becoming recognized as the world's primary social network. Yahoo shuttered the service after only a year. Similarly, Facebook's Smartlists is an obvious repackaging of Google+'s major innovation, Circles. Kind of like that time that Yahoo repackaged Yahoo Mail as Ymail in a naked attempt to compete with the new rising star Gmail. All the while, Yahoo survived because of their Herculean traffic numbers and the display ad revenue that came with that.

As Elgan says, Facebook's ability to make money means that it probably won't disappear or fail, but like Yahoo, it will continue to become painfully boring:

Yahoo has no vision. It has no purpose. It's dispensable. Yahoo continues like a zombie, animated by the life it once had.

And that's what Facebook is becoming. Yes, they'll continue to have users. And yes, they'll continue to make money. But Facebook is looking increasingly like a one-trick pony that doesn't have the vision to reinvent itself for the post-Facebook era.

Some people don't think this is such a big problem. Farhad Manjoo at Slate lauds Facebook's new Smartlists and Subscribe button, pointing out that lax patent laws on the web mean that "Facebook is free to grab what it wants with both fists." Manjoo thinks that Facebook does it well, too. "I hope they keep at it," he continues. "If there's a good feature on some other social network, why should I have to leave Facebook to get it?"

The obvious reason is that Facebook doesn't actually copy others' products that well--or to take a more objective route, users simply aren't catching on to the new copycat features. In a trajectory that very much resembles Yahoo Mash, Facebook launched and killed its Groupon and Foursquare copycats within a year. Facebook announced last October that it was going to reinvent email and messaging, but it didn't quite work out that way. "Facebook hasn't talked about it very much since," points out Matt Rosoff at Business Insider. "And we've never seen a message from a facebook.com address in any of our other email inboxes." Rosoff actually made a whole slideshow of examples of Facebook's failed copycat version. (We recommend viewing it as one page.)

Who knows. With Carol Bartz's departure and all kinds of chatter about some Silicon Valley savior swooping in to save the company, Yahoo could make an amazing turn around, and give Facebook's critics food for thought. In the meantime, we're still using Gmail, reading Twitter and checking in on Foursquare. Meanwhile, Facebook is still fantastic for looking up college friends' phone numbers. And Yahoo still has a lot of ads.