Blockstack's initial coin offering (ICO) has officially closed, with the company announcing today it has raised $50 million through the sale of 440 million tokens.

Launched in November, the sale saw investors – including Union Square Ventures (USV), Foundation Capital, Lux Capital, Winklevoss Capital, Blockchain Capital, Digital Currency Group, Y Combinator partner Qasar Younis, Techcrunch founder Michael Arrington and Digg founder Kevin Rose – fund Blockstack's particular vision for a decentralized web built on blockchain technology.

Still, in statements, the Blockstack team was keen to stress that those involved are best thought of as long-term partners, all of whom agreed to take long positions in its new cryptocurrency.

For example, Blockstack said the largest investment came from an undisclosed endowment, which secured a $6 million allocation after agreeing to a four-year lock-up for half of its allocation (other investors had a two-year lockup, with a $3 million maximum).

Co-founder Muneeb Ali told CoinDesk:

Elsewhere, Blockstack provided a host of metrics on the offering. More than 800 people and entities were said to have participated in the public token sale (a pre-sale was not offered), where the minimum investment was $3,000. The median investment was $6,140.

Further, Blockstack was keen to note its own guarantees.

Of the funds acquired, only $10 million will be immediately available to the company, as the firm has agreed to a lock-up until milestones are hit. The next $20 million will be released when its board of advisors verifies it has delivered the next version of its product, a network that integrates the token.

The final $20 million will be secured when it achieves its final milestone, one million verified users.

Founded in 2013, Blockstack has been building a decentralized architecture for publishing on the internet, one designed around user control. To realize that goal, the "stacks" token will run on Blockstack's virtualchain technology, according to the white paper.

Co-founder Ryan Shea told CoinDesk:

Disclosure: CoinDesk is a subsidiary of Digital Currency Group, which has an ownership stake in Blockstack.

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