Slack is a new team collaboration app but goes beyond the traditional enterprise communication app features. The company wants to be the central repository for all company communication. With its advanced search and file-sharing functionalities, it currently integrates with more than 60 other businesses including Google Drive, Dropbox, and Twitter.

Slack was co-founded by Stewart Butterfield. Butterfield is best known as a cofounder of Flickr, which was sold to Yahoo.

In the first six months of its official launch, Slack recorded over 125,000 active users and 13,000 active teams. As of October 2014,  30,000+ active teams were using Slack with 268,000 daily active users.

Slack raised $120 million last October at a valuation, including the fresh capital, of $1.12 billion. Kleiner Perkins Caufield & Byers and Google Ventures led the financing, with participation from existing investors Andreessen Horowitz, Accel Partners and The Social+Capital Partnership.

Here are a few reasons why Slack has been growing like crazy and everything the company has been doing right. These may not have been the only reasons why Slack took off at such an amazing growth rate.

1. “I think we got on a problem that’s been under everyone’s noses but they just haven’t noticed,” Butterfield, Slack’s CEO, told Business Insider. “The advantages of a centralized communication platform for internal use is so huge that everyone will be using one within the next 10 years.”

2. “Our growth has been very good. But so far, it’s been happening to us, as opposed to us doing it in a deliberate way. But now we get to do it in a deliberate way,” Butterfield said.

3. “Our subscription revenue is growing about 8 percent monthly, before we add new sales,” says Slack’s business analytics lead Josh Pritchard. “This is, as far as I know, unheard for an enterprise SaaS company less than seven months after launch.” Slack’s user retention stands at an astonishing 93 percent.

4. Slack didn’t run run any advertising or marketing campaigns when it launched. “I have never seen a viral enterprise app takeoff like this before — all word of mouth.”  billionaire investor Marc Andreessen once tweeted

slack growth rate

5. “I think Twitter makes a huge difference. People get excited about it and they post it to Twitter, and that obviously works a lot faster and better than the individual 1-on-1 kind of recommendations.

Every day we get hundreds of tweets, and dozens that are really enthusiastic about our product. If it wasn’t for Twitter, I think it would have been much harder for us to grow as fast as we did.” according to Butterfield in an interview with Business Insider.

6. “Slack is simple enough for new users to jump right in. Many competing group-messaging or collaboration services are either over-engineered or poorly designed. Slack has a great balance.” says Quartz

7. Slack is popular with the press. It has been embraced by all the trendy and brave young media properties—Vox Media, Buzzfeed, Medium and Gawker Media are all paying customers.

8. According to Wired “Slack is so beloved that some companies have begun mentioning it as an employment perk alongside on-site massages and bottomless bacon-tray Fridays in their job listings,”

9. The slack habit. “The Slack team understood that it is much easier to displace an existing habit than to create an entirely new one. Slack doesn’t try to radically change user behavior. Instead, it makes existing behaviors easier and more efficient.” says Nir Eyal and Ciara Byrne.

The author of “Hooked: How to Build Habit-Forming Products” and Ciara continue to say in a post that “Slack leads users repeatedly through a cycle called a “hook.” The four steps of the hook include a trigger, action, reward, and investment, and through successive passes through these hooks, the new habit is formed.

10. “Slack has an actually-useful free service. The key to growth is to remove as much friction as possible, in both product design and economics. Many groups (including Quartz) are happily communicating on Slack for free.” Quartz