Facebook has just unveiled Poke, a messaging app for video, photos or even plain old text messages, where the messages are destroyed several seconds after they arrive. That's precisely how the increasingly popular Snapchat app works and that's no coincidence.

"With the Poke app, you can poke or send a message, photo, or video to Facebook friends to share what you're up to in a lightweight way," Facebook explains.

"You can poke an individual friend or several at once. Each message expires after a specific time you've set, either 1, 3, 5 or 10 seconds. When time runs out, the message disappears from the app," it adds.

Facebook is the behemoth of the social space and it's beginning to flex its muscles. Lately, Facebook started focusing on the mobile space and, perhaps a good idea, is more keen on creating interesting products rather than just expand the monolithic Facebook as much as possible.

The dedicated Facebook Messenger app is the perfect example; all of its features are part of the proper Facebook app, but Messenger is more streamlined and clearer in its purposes. If you just want to send a message or see what others sent you, using Messenger is faster.

It goes beyond this though; there was also a Facebook Camera app that looked a lot like Instagram. Of course, there's also Instagram, which Facebook acquired several months ago but which it's keeping independent.

Now, there's also Facebook Poke, a Snapchat clone. Snapchat allows users to send self-destructing images or videos. Anything you share is gone a few seconds after it reaches its destination. Obviously, it's very popular with the young ones.

Whether it's popular because of its features or precisely because it isn't Facebook remains to be seen.

UPDATE: Poke isn't proving that popular, while Snapchat remains one of the most downloaded apps in the App Store, so that question has been answered, for now.

Facebook Poke is a complete clone of Snapchat, so all the features are there and the UI may even be better. But it's still Facebook; you'll have to use your Facebook name and so on.

Beyond the app itself, which may or may not be popular, Poke is a message. Word is, Facebook tried to buy Snapchat a few weeks ago. The app maker decided to stay independent. So Facebook set out and built Poke, again, almost an exact replica of Snapchat, in just 12 days. There's no clearer message than that, join Facebook or be destroyed.