The Social

Facebook announced Wednesday morning that its in-browser Facebook Chat feature is now live to all members, over two weeks after it first debuted to a limited number of users.

It was clear that Facebook was concerned with the stability of the chat application, first debuting it on a Sunday when many members--not to mention tech bloggers eager to report any flaw or bug--might not be at their computers.

The social network then rolled out Facebook Chat incrementally, with different "networks" on the site--geographic regions, colleges, companies--gaining access to it before others so that the new feature could stay under control. Some had the feature as early as April 6; a number of large networks couldn't access it until very recently.

Facebook now has nearly 70 million users.

Facebook chose a Sunday afternoon, when much of the tech blogger corps was pleasantly enjoying real life (we can hope), to start rolling out its previously announced instant-messaging client. That's likely no coincidence: this is a major new feature for the social-networking site, and debuting it on a weekend afternoon probably ensured a smoother integration.

A Facebook employee told me in the days before the launch that it was "a big challenge" to get ready to roll out Facebook Chat to the site's 67 million members. Because of that, Facebook has opted for a gradual rollout rather than a large-scale launch to all members at one time. The in-browser client, which lets members of the site talk to their Facebook friends who are logged in, is still not live on many Facebook accounts--mine, for example.

Facebook has earned criticism from some performance monitoring firms for unreliability, and the Techmeme set is notorious for not cutting companies a whole lot of slack--remember when Google relaunched Blogger late in 2006? After "Beacongate," Facebook doesn't need another PR debacle.

And as an extra precaution, the debut version of the application is extremely light. There is no support for external IM clients yet, though the company has said it's exploring Jabber support. For now, that means it probably won't be pulling chat-friendly Web users away from their existing services (the AIMs, Yahoos, and Google Talks of the world) and clients like Meebo and Adium. Yet.

In that respect, the launch of Facebook Chat is much like the history of Facebook itself. The service famously started in a Harvard dorm and was limited to students with Harvard e-mail addresses before gradually rolling out to other universities, then companies, and finally the general public.

Considering the site remains the toast of the town all over Silicon Valley nearly a year after the launch of its developer platform thrust it into the spotlight, it looks like they've been pretty successful in spite of that caution.

The new addition to Facebook likely won't have the impact of drawing new members or "converting" people from other social networks. Where it will make a difference, however, is on the amount of time that members spend on the site, which can make a big difference for advertisers.

On the flip side, this could spell doom for those hours you whittle away on Facebook at the office all day. If your boss hasn't blocked access to the site yet, browser-based instant messaging could be the final straw.