Image source: Snap Inc.

Snap Inc. recently entered a confidential filing to go public in 2017 at a valuation of about $25 billion. That's important news for investors because Snap is growing at a rapid pace, and could become an even bigger player in the messaging app space in the coming years.

For reference, Snap Inc. is the name of the company (which used be called Snapchat as of a few months ago), while Snapchat now refers to the company's messaging app. If you don't know much about Snap, you're not alone (you can read a simple primer here).

To get a better understanding of how big Snap's IPO could be, let's take a look at a few charts showing how significant the company's app is, and how that's helping to build the company's long-term opportunities. The charts below will show you that the Snapchat messaging app is growing fast and holding its own among bigger players in the messaging and social media space like Facebook (META 0.20%) and Twitter (TWTR).

Monthly active users are skyrocketing

Three short years ago Snap had just 33 million monthly active users, but that number shot up to 301 million this year. Take a look of the company's monthly active user growth over the past few years:

Image source: Statista

Now, to be fair, this is still quite a few less than, say, Facebook's monthly active users, which were 1.79 billionin the third quarter 2016. But Snap's scale really comes into view when you consider that Twitter -- which has been around since 2006 -- has just 16 million more monthly active users than Snap.

And Snap's app is already climbing in the ranks among important apps. In July of this year, the company ranked among the top 15 mobile apps, according to comScore and Tech Crunch. That's no easy feat considering that it put the app in a list with Facebook, Twitter, Facebook Messenger, YouTube, Instagram, Google Maps, etc. Remember, Snap released its app just five years ago. 

More than just logging in

Snap doesn't just have a popular messaging app, though. Users (called Snapchatters) are sending lots of snaps (messages) in the app and spending lots of time there, too.

Snapchatters watch nearly 10 billion videos on the app everyday, according to Bloomberg, and all of those video views are translating into substantial time spent in the app as well. Here's how daily usage compares to Facebook's apps (including Messenger and Instagram), YouTube and Twitter:

Data sources: New York Times and Business Insider.

Facebook owns about 50 minutes of its users' day through its Facebook, Messenger, and Instragram apps (but excluding WhatsApp), while YouTube takes 17 minutes, and Twitter grabs just one minute, according to comScore data reported by The New York Times.. Meanwhile, Snap told Business Insider earlier this year that its users spend an average of 25 to 30 minutes in the app every day. 

A potentially huge opportunity

Keeping track of the amount of users and how long they spend in the Snapchat app is important as the company looks ahead to its IPO. At the company's current IPO valuation, Snap would be the third-largest tech IPO in recent history:

Image source: Statista.

But even more important is the company's current revenue, and projected revenue for the coming year. Snap will bring in between $250 million to $300 million in revenue this year, and expects that to hit up to $1 billion by the end of 2017. 

Snap isn't profitable right now, and much of its money is being funneled back into the company's growth. If Snap hits $300 million in revenue this year, it'll be a 400% increase year over year. And if it ends up hitting its projected $1 billion in 2017, then that'll represent a 233% to 300% increase year over year. Snap is a young and growing company, so that's exactly the type of revenue growth investors should be looking for. 

The company makes most of its revenue through selling ads in the Snapchat app, and the company says its ads were viewed between 500,000 to 1 million times every day in 2015 and have an engage rate that's five times higher than click-through rates for mobile ads. 

It's clear that Snap is doing a good job growing its Snapchat users and revenue. The big question will be if the company can continue on this trend and eventually turn all of that into a profit. For now, Snap's stellar growth should be enough for investors to give the company a hard look as the the company's IPO quickly approaches.