The techno-spies at Mashable have done it again...ferreted out a deep, dark social networking secret.

Twitter, the popular microblogging social networking Web site, is reportedly testing a Facebook-like messaging wall on user's profile pages. This will allow Twitterers to send public tweets in the form of replies to specific users directly from their profile pages, reported Mashable. Twitter is reported to be testing the new feature with a limited number of users. There is no word yet on when and how the feature will be widely deployed (or if it will be widely deployed, for that matter).

Twitter spokeswoman Carolyn Penner told Mashable that the new feature is being designed to “make it easier for users to engage with each other” on Twitter, which is often accused of being counter-intuitive to use and complicated for neophyte users to understand. For this reason, while Twitter has a very high membership rate – people who create accounts – only a fraction of those people use the service on a regular basis.

Writes Business Insider's Pascal-Emmanuel Gobry, “Once people reach a certain threshold of engagement with Twitter, they stay engaged users for a long while. If they don't, they sort of drop off the map. So anything that boosts engagement is a great idea.”

Twitter clearly hopes to make posting processes – in particular, replying to a post – a little more transparent in response to its critics, and to offer users a feature they've gotten used to (and like) on Facebook.

Since its inception in 2006, Twitter has gained popularity worldwide and is estimated to have 200 million users (though not all those are active users), generating 200 million tweets a day and handling over 1.6 billion search queries per day.