meebologo1.pngInstant messaging service Meebo has opened its platform to third party developers, which will put it in competition with Facebook, Google and other communications platforms. The new applications on Meebo already include voice and video services.

We wrote last week, here, that Meebo had a great opportunity to become a platform. It’s an instant messaging service that lets people IM across multiple protocols, including AIM, Yahoo, Gtalk and MSN. It’s web-based, requiring no download. It has introduced group chat rooms, widgets and other features in an effort to combine real-time collaboration with social networking.

Meebo Platform could yield useful applications not available on Facebook because Meebo is built on real-time interaction whereas Facebook is an asynchronous communication tool.

Meebo’s platform will include application programming interfaces to give developers access to user data. It is working with four partners, announced at the company’s two-year anniversary party tonight.

Tokbox is providing video chat between users, with Ustream for one-to-many live video broadcasting, Pudding Media for one-to-one VoIP calls and TalkShoe for online conference calls.

As I wrote last week, compelling applications built for Meebo could pull in non-Meebo users. The switching costs from an IM client like AIM to Meebo is low because Meebo has many of the same features.

RockYou CTO and co-founder Jia Shen said he believes the IM friend list represents a more intimate and accurate social graph than what Facebook or MySpace have. That’s because it’s more likely to contain friends and contacts that a person actually interacts with. Shen said that it would be hard for other platforms to replicate the real-time nature of the Meebo Platform. RockYou is working on Meebo applications.

At the launch event, Sequoia VC and Meebo investor Roelof Botha said people evaluating Meebo should consider its reach is not confined to its more than 6 million monthly users spending on average 40 minutes per day on the site. In all, Meebo accesses presence information of tens of millions of people on Meebo users’ buddy lists. This reach provides expansion room and an opportunity for developers to reach millions more users via buddy lists.

The applications already available on the platform can used without requiring logging into Meebo, but it does require visiting a Meebo link. Future applications like games might require logging into Meebo, building user lock-in. Meebo could build a sustainable competitive advantage with network effects, as users and their friends adopt more applications. For example, if a group of friends rely on TokBox on Meebo for video chat, why switch to something else when you rely on connecting with your friends using Meebo applications?

In particular, switching costs could be high for users leaving Meebo applications that build on or rely on stored past activity.

Developers will be able to monetize the application. Meebo will sell ads directly into the applications and keep half the revenue.

It will also have third parties offer office, casual games, e-commerce and other applications.

Applications will need to rely on Flash or Javascript. Developers can sign up here to participate.

The company has grown quickly since it launched. Now, it says more than six million people log in monthly, with more than one million people spending up to two and a half hours logged in every day.

Meebo is backed by Draper Fisher Jurvetson and Sequoia Capital.

[Disclosure: Doug Sherrets owns a small number of Facebook shares.]

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