Facebook will pay top dollar to survive this fickle world of social media software, and will pay even more to throttle the competition. After two years of speculating who would buy the instant-messenger service WhatsApp, it was Facebook that made an irrefutable offer of $19 billion.

If you feel that’s a ridiculously large sum to shell out for anything but the moon, see here for the complete breakdown of Facebook’s multi-billion dollar proposal (there’s lots of stock shares involved).

Ads next for WhatsApp?

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The next question is, what will happen to WhatsApp should the Facebook deal go through as planned? Two obvious options:

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• WhatsApp could be shut down and its technology fully incorporated into Facebook’s own chat service
• WhatsApp could remain a standalone service and continue as is

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A likely option is a hybrid of the two, where WhatsApp could eventually be monetized through a combination of direct services and advertising. Though Facebook CEO Mark Zuckerberg insists that WhatsApp will not be turned into an advertising platform, its data-rich consumer activity is still valuable to Facebook’s larger advertising and monetization goals.

“Our explicit strategy for the next several years is to focus on growing and connecting everyone in the world,” Zuckerberg said. Currently, WhatsApp has a strong presence internationally with 450 million monthly users, but it’s a fragmented market with many competitors. Outpacing them right now is critical, Facebook’s CEO explained. ”Once we get to being a service with 1 billion, 2 billion, 3 billion people, there are many clear ways that we can monetize.”

Facebook’s certainly building an armory of mobile applications, including the still buzzworthy Instagram for $1 billion. Staying true to its word, Facebook’s done little to disrupt the Instagram experience. So we can trust Zuck when he says WhatsApp will remain largely the same even under his guidance – at least for a little while.

Nevertheless, those weary of WhatsApp’s decision to sell out will be on the hunt for alternatives. Here’s a few to consider:

4 alternatives to WhatsApp

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InstaMessage

This messaging app lets Instagram users talk to other Instagram users privately.  The great thing is that you don’t need to sign up for anything, as you only need to use your Instagram account to start chatting with people and celebrities, disciver other InstaMessage users nearby, browse profiles as well as block other InstaMessage users from seeing your profile.

Kik Messenger

This free messaging app is available for iOS, Android, Windows Phone, Ovi and BlackBerrysmartphones.  Kik now boasts of 30 million users, and claims that they are adding as much as 100,000 users per day.

Viber

This free messaging app allows users to send texts, call, send photos as well as share user’s location to their contacts via WiFi or 3G.  Users do not need to register, as a user’s phone number serves as his Viber ID.  Also, contacts need not be exported since it uses your existing contacts sheet on your mobile device.  It is available for iOS, Android, Windows Phone, Ovi,BlackBerry and Bada.

Voxer

This is a cool app that turns your device into a Walkie Talkie as well as allow users to send messages, photos as well as make a call using the app, and group chat.  It is available for iOS and Android.

Looking for more privacy with your chat activities? Check out Snapchat alternatives here.