The New York-based company pulled back from a separate fundraising effort a year ago. At the time, rumors swirled of a big round with a valuation of between $300 million and $400 million. But that round never happened. When asked about it later, co-CEO and co-founder Katia Beauchamp’s response was appropriately politic: Birchbox did not need to raise more capital. “We’re on the path to being independent forever,” she told me.

Prior to this, the subscription startup has only raised $12 million in venture backing from Accel Partners, First Round Capital, Harrison Metal Capital, Forerunner Ventures, Red Swan, Consigliere Brand Capital, and Lerer Ventures. It’s not much cash for a company with 250 employees and more than $80 million in revenue. (Compare that to Warby Parker, which has raised $116 million. The two commerce companies are often talked about in the same breath because they’re both fast-growing consumer-facing commerce companies in New York, both started in 2010 with co-founders who met at business school.)

Birchbox’s growth has been impressive: Last year the company doubled its subscriber base to 400,000. The four-year-old company had between $80 million and $100 million in revenue in 2013, one source said. Birchbox has also expanded to Europe with the acquisition of JolieBox, and expanded into the men’s category with Birchbox Man. Last year Birchbox experimented with branded boxes, as well as more expensive lifestyle boxes for occasions like hosting a dinner party or New Year’s Eve.

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But competition is fierce. Glossybox, Birchbox’s European competitor (created by famous clone artists the Samwer Brothers), has raised $72.5 million from the Samwers’ Rocket Internet and Holtzbrinck Ventures Investment AB Kinnevik. The company has shipped two million boxes. Likewise, Ipsy, a California-based competitor, has gained steam with “glam bags” that include full-sized products for the same price.

Beauty has not been a large category for online shopping, as customers like to try products in stores before they purchase them. Birchbox’s model of sending beauty samples allows them to do that without setting foot in a store. In that way, Birchbox has essentially convinced subscribers to pay $10 per month to be marketed to. The subscriptions alone represent a significant part of Birchbox’s income, and growth in subscribers has actually accelerated in the last year, one source says.

Aside from subscriptions, Birchbox’s revenue also depends on its subscribers buying full-sized versions of the products on Birchbox.com. As of last year, half of all subscribers had purchased a full-sized product.

But as the company increases its subscribers, it faces challenges in finding new brands that can invest enough money into a sampling program so large. The company says it does not pay for the samples it sends out. Birchbox segments its subscribers into groups which get different boxes based on their preferences, so that small, boutique brands can afford to participate.

A Birchbox representative declined to comment.