Slack, the Startup Looking to Kill Email, Is Now Reportedly Worth $2 Billion That's double its valuation from six months ago.

Slack, an internal communication app designed to allow businesses to chat and collaborate at work, is in in the process of raising a new funding round that values the company at $2 billion, Bloomberg reports.

If accurate, this means Slack's valuation has nearly doubled in the span of six months. (Last year, the startup raised $120 million at a valuation of $1.1 billion from high-profile venture investors, including Kleiner Perkins Caufield & Byers and Google Ventures.)

While impressive, it's not surprising; Slack has been experiencing explosive growth. Just a year old, Slack is used by about 500,000 people every day, a number that is rapidly growing. Earlier this month, Slack CEO Stewart Butterfield told The New York Times that the company's user base is doubling every three months and by the end of the year, he predicted the app will be used by 2 to 3 million people.

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Slack aims to replace email by providing companies with more nuanced ways to share information. The app supports private messaging as well as group chats; it's built to work across devices and integrate with outside services such as Google Drive and Twitter; baked-in features include the automatic archiving of all communications on the platform, as well as the ability to search all interactions for keywords.

The idea is to reduce pointless emails via the introduction of multiple, tailored channels of communication.

So far, a wide range of customers have jumped on the Slack bandwagon, including tech companies (Airbnb, eBay) media companies (The New York Times, BuzzFeed), large corporations (Walmart, Comcast) and smaller businesses (Blue Bottle Coffee).

While not the right fit for every business, Butterfield recently told NeimanLab: "It works well when there's a lot of internal communication: people on the team talking to other people on the team."

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