Privacy is a major concern. But, also, functionality is very important. If you want to topple Facebook do two things:

Guarantee privacy and revolutionize functionality. Here's how:

Privacy; The Zero-Knowledge Database. By relying upon the client to compute deterministic indexes based upon user-input, you can abstract the relations from the database into the client space. The result is that you have two items, say a pet and owner that look like this: Pet: id afb142, name Spot Owner: id dsf513, name Data

When Data logs in with his username and password, those values are never sent to the server -- instead, they're used along with other information to create keys <afb142> and <dsf513>. This process is deterministic given the sign-on data, but difficult to reverse-engineer (a one-way, trapdoor function or hash). So, Data knows his pet is Spot, but anyone else, even with full access to the database, doesn't.

This database design facilitates collaborative filtering, demographics analysis, et cetera.

On Functionality: Pro-active social networking. Facebook loses because it tells you what you know (or what your friends know). We've seen that globalization's promise of expanding our horizons is wrong -- we only become more niched. Yet, despite being very focused on a few topics, no one is exploiting this in a useful way. If you know that I enjoy older Country music and that I like a well-made cocktail, why can't your social networking site hook me up with a suggestion about what to do this weekend?

Right now, most people hear about new things through their contacts. But, their contacts have to be introduced to them through exploration or diffusion through their contacts. This process is slow and requires extensive contact networks of people with similar interest to find one another. The system, however, knows who likes Hank Williams and it knows who likes a perfect Vesper. Through some basic analysis; why can't it suggest to me a bar and a band this weekend based upon what other people with similar taste are doing?

Imagine waking up in the morning and logging into NotFacebook... it tells you about a few articles on HN, Reddit, and a number of blogs. Some are bloggers you know and love while others are new-to-you bloggers writing about subjects you enjoy. The system also recommends dinner at a restaurant that's recently enjoyed positive reviews from your fellow mushroom-hating, meat-loving epicureans. I knows you and Sam are free (Sam has similar taste, after all, and is a good friend of yours).

That would kill Facebook, I think.

They have firmly situated themselves as the dominant social network, and I don't see this changing for a long time.

But even now, Facebook's influence on our lives is fading away. As nearly everyone starts using it, and as everyone starts forming connections with anyone they have briefly met, it's power becomes greatly diluted. In many ways, it is becoming LinkedIn - a sterile place where everyone only puts forth their public persona.

It's certainly more complex than that, to do a real analysis you need to go feature by feature. Some become more useful as everyone connects (market place, events, causes, messaging, chat) but other things clearly suffer. Facebook used to be a place to share the kind of personal photos only your good friends see, but no longer. Your status used to be a very personal microblog, now you have to be much more careful.

Facebook used to be about your personal life, and more and more it's about your public life. Most teenagers will probably reject using Facebook in meaningful ways because of this. And that's the beginning of the end for Facebook as we know it.

Soon it will be nothing but infrastructure for our public net existence. Sure they will continue to make money, but I do expect the people who used to spend hours a day on it to start channeling their attention elsewhere.

If you want to compete with Facebook, become the tool that lets people follow each others' personal lives again. Let Facebook continue on it's trajectory to become a digital address book.

Nothing is permanent, of course, and on the web things can change in a flash.

That being said, they are making obvious moves to continue to add to their defensibility. Their understanding and manipulation of the network effect is unparalleled by any other company out there. It will be a long time before they go.

I would suspect the thing that replaces them is nothing we can quite imagine. I do think facebook has probably "won" social networking in the browser space, the company that beats facebook will have to have a product that connects people better, and I would argue one that offers an experience that transcends what is possible in the browser. Within the current browser-based paradigm facebook is extraordinarily competitive and I do not expect them to lose there, but of course that goes without saying. The key to replacing a company like facebook is finding a new space where it is too big to pivot to compete in, and dominating that space. Right now facebook's organization and processes are setup to completely dominate the browser and innovation in that sector (from recruitment to product design). You'd need to force them to shift gears more quickly than they could, and I think a new platform would probably be the best bet.

But anything anyone says on this thread is wild speculation and should be taken with a grain of salt.

I don't have a direct answer to the first part of your question, but as for the, "if anything?" part...

It's a sure thing. Remember when people used to talk about what could possibly unseat MySpace, if anything?

30 days since the last blog post, and nearly $180,000 later we still wait for Diaspora. However, you can get a t-shirt they've apparently been pimping out on twitter (http://twitter.com/joindiaspora/statuses/16711664582).

I hate to be debbie downer on this one, but ~$180,000 is a lot of money to be contributed to a project like this, which from the technical aspects that we know so far (which of itself does not say a lot for something with it's ambitions, and given the name which seems to be almost a southpaw sucker punch to Facebook with the exodus/diaspora of users), might not even gain any sort of mainstream traction to be worthy of more than a cursory blog post from CNet once it launches.

When the social web has a well defined and widely adopted standard, then Facebook will become just another social site. In short, we need an accepted standard like HTML or RSS for social updates.

I would like to use Buzz/Twitter/Identica/whatever to post one update. And then all my social connections will be immediately notified of the update regardless of what client or website they prefer to use.

If people start getting racked with real-world consequences because of things they put on Facebook, like lost work opportunities, legal ramifications, harm to their reputation, and so forth to a point where the average person (non-techies) becomes concerned about privacy to the point of avoiding social networks like Facebook entirely then Facebook's growth model is going to be in jeopardy. As for what will replace Facebook in the event that this happens - probably closed networks along the lines of LinkedIn.

I'd say it'll take a few years of things going the way they are now before the public at large starts taking their privacy a little more seriously.

I had this idea of a real social event, say on campuses, etc. that would be called "Quit Facebook Party". It would be a themed party where people delete their accounts permanently, the process being projected on the wall for others to see. With the social validation people would find it easier to get over their addiction and stop wasting time on FB. Once it became "cool" to not be on FB, it could spread just as fast as being on it did earlier.

Topple or not, I am sure Google's version of facebook can make much more money with comparitively much less users.

a great API like twitter. facebook is still far from good for developers: always changing their apis without notice, slow response times and limited functionality (do they already have any type of search api that works across all the website?)

Yes, and they'll do it themselves with their hubris.