The biggest problem with Twitter is that it's never had much innovation, an analyst once told me.

"If you used Twitter the first day it existed and then slipped into a coma for eight years and woke up today, you'd recognize the platform. It looks very much the same," then-Forrester Research analyst Nate Elliott told me in early 2015. "While Facebook innovates every day and constantly offers users new ways to engage on the site, Twitter's basically the same exact thing it's always been."

I'm reminded of this conversation -- which is just as apt today as it was two years ago -- as I read headlines from reporters and analysts who are quick to compare Snap Inc. to Twitter. The premise of the comparison is a recent slowing in Snapchat's user growth disclosed in the company's S-1 filing. To some minds, this deceleration is reminiscent of Twitter, which has demonstrated little ability to increase its user base since first going public in late 2013.

That's where the comparison starts and stops, because weak user growth in and of itself isn't a problem. It just seems that way because it's often a symptom of the real problem: a tech company's inability to create innovative new features and products. That's a problem Snap doesn't have under CEO Evan Spiegel, who has proved time and again he is all about making things new. On that score, Twitter and Snap couldn't be more different.

As Elliott pointed out two years ago, Twitter hasn't changed much since it first came into existence in 2006. To this day, Twitter is a service based on 140-character messages that you see in a reverse-chronological timeline. Certainly, Twitter has added little wrinkles here and there -- you can now watch NFL games live on the service, there's some algorithmic surfacing of tweets deemed relevant to your interests, and if you wish to avoid online harassment, you can mute whatever terms offend you. But by and large, Twitter is as it always has been, a place where you can send out micro-messages to the world. Twitter has been so afraid to reinvent itself that it is now practically on life support as a result.

Snapchat, on the other hand, is a drastically different app than it was even just a few years ago, and as a company, it has completely changed.

When Snapchat was first going mainstream in 2012 and 2013, it was largely known as "that sexting app." Its primary purpose was to send your friends photos and videos that you didn't want hanging around. You couldn't read a story about Snapchat without reading the word "ephemeral." Practically none of those characterizations can be used to describe Snapchat today

Just look at one of the additions to Snapchat in the last year: Memories. This feature is the exact antithesis of what Snapchat was five years ago. Back then, you wanted your snaps to go away. Now, Snapchat makes it easy for you to share an old photo or video.

This kind of innovation is no anomaly. Since 2012, Snapchat has changed the premise of its app over and over again. In 2013, it added Stories so you could broadcast your daily activities with all of your friends for 24 hours. In 2015, the app introduced Discover, giving its users a new way to access media. And last year, Snapchat rebranded itself as Snap when it introduced Spectacles, its first foray into hardware. It's not likely to be the last, with Spiegel now calling Snap a camera company, not a social media or messaging service.

Time and again, Spiegel has spotted where user behavior is heading and placed Snap in a position to benefit from it. This is something Twitter has largely been unable to master. Even when Twitter has noticed an opportunity, it has always tripped after gaining a head start -- I'm talking about bite-size videos (see: Vine) and live streaming (see: Periscope).

When Sony Pictures was hacked in 2014, some leaked emails involved Snapchat. It showed that the company had paid tens of millions of dollars in three acquisitions: one was, a QR code scanning company, another was AddLive, a real-time video chat startup, and the third was Vergence Labs, which made technology similar to that of Google Glass. and AddLive were turned into features for Snapchat, and Vergence Labs was clearly a predecessor for Spectacles. In this respect, Spiegel has shown he possesses vision and an ability to spot talent and pull the trigger on important acquisitions that merits comparisons to Facebook CEO Mark Zuckerberg.

Without a doubt, Snap has its challenges. It's concerning that such a young app could already be facing user-growth problems. It's troubling just how fiercely Facebook is attacking Snapchat, and it's alarming that Spiegel and co-founder Bobby Murphy do not want to give shareholders any voting power whatsoever.

Snap must overcome these issues, but as analysts and investors comb through the company's S-1 filing for nits, it's important to keep in mind what Spiegel and Snap have already shown when it comes to innovation.