Octazen's contact importer helped Facebook make its userbase viral.

Facebook last week acquired a small Malaysian startup called Octazen Solutions, maker of a contact importer that the social network had already been using to grow its number of users by encouraging them to invite their email contacts. Spokesperson Larry Yu described the buy as a “talent acquisition,” saying Octazen’s two employees have joined Facebook as engineers. As he put it in a company statement on the acquisition he sent via email:

“We’ve admired the engineering team’s efforts for some time now and this is part of our ongoing effort to add experienced, accomplished technical talent to help drive the company forward in its efforts to be the central way for people to connect and share information.”

Octazen’s software helps sites like Facebook grow by making it easy for users to invite their contacts on other services. When Octazen receives an email address and password it fetches a list of contacts and puts them in an array for customers to use and store (and hopefully not abuse!). Octazen has taken down most of its site in light of the acquisition, but archived versions show it charged for software licenses between $39 and $200 per domain server plus a yearly update fee.

Octazen said in a message posted on its site that it is no longer accepting new customers and that it will “enter a transition period to wind down operations.”

Facebook, which now has more than 400 million users including 250 million added in the last year alone, has kept fairly quiet on the acquisition front, focusing primarily on talent buys rather than products (though it did discuss purchasing its rival Twitter). Previously it bought Parakey and FriendFeed, whose former execs now work on Facebook-originated products rather than their own.

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