Mobile messaging has long been a hot space in technology, and Facebook's jaw-dropping $16 billion acquisition of WhatsApp underscores the opportunity in this buzzy field.
WhatsApp -- which lets users send text, video and voice messages via Internet data instead of "charging" the messages to users' texting plans, even to international recipients -- and its dozens of competitors worldwide are capitalizing on big global trends in mobile. Facebook and others want to cash in.
(Read more: Why WhatsApp's $16 billion price tag makes sense)
"This WhatsApp deal even gets into the upper echelon of the biggest-ever business deals," said Brian Blau, the research director of consumer technologies at tech-focused research firm Gartner. "It shows just how seriously Facebook sees this space."
Here are four reasons mobile messaging is huge in tech right now:
Messaging apps as social networks. WhatsApp and its ilk -- China's WeChat and Japan's KakaoTalk, as well as Kik, Line and many more -- let people send each other texts, videos, photos and other content to connect one-on-one or as a group.
(Read more: Is WhatsApp deal a reason to short Facebook?)
Sounds a little like Facebook, doesn't it?
"We call them messaging apps, but these are absolutely social networks," said Brent Iadarola, the global research director of mobile and wireless at Frost & Sullivan. "WhatsApp and other apps have grown this robust ecosystem, and Facebook clearly views that as a social network on a smaller scale."
The scale may be smaller in terms of the number of people connected in a given chat, but the amount of content shared is staggering. WhatsApp's users are uploading daily an average of 600 million photos, 200 million voice messages and 100 million video messages.
"WhatsApp may have a different type of user and a different type of usage scenario, but it's still core social," said Blau, the Gartner analyst. "You can easily see how WhatsApp fits into the Facebook story."