Chinese e-commerce giant Alibaba has filed to go public in the United States in what is expected to be one of the largest stock listings in history. So what's the big deal about a company that many people in the U.S. have probably never even heard of (at least until now)? In the accompanying video, Yahoo Finance Editor-in-Chief and I answer that question. Here are a few of the key takeaways. (Disclosure: Yahoo owns a 22.6% stake in Alibaba.)

1. It's huge. Alibaba is like  Amazon (AMZN) and Ebay (EBAY) on steroids. In 2013 $248 billion was spent at the site -- about 30% more than was spent on Amazon and eBay combined, according to Forrester research. It's the world's largest online marketplace, with 231 million active buyers a year, reports the Wall Street Journal, and accounted for 80% of all Chinese e-commerce transactions last year, according to multiple research firms.

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2. It's very profitable. Alibaba makes 50 cents on every dollar of revenue it collects. Its main Chinese retail sites include Taobao -- a bazaar-like marketplace where eight million merchants sell their goods -- and TMall, which sells higher-end Western brands such as Nike (NKE) and Apple (AAPL).

The company makes money through sales commissions and advertising by merchants. Its revenue rose 62% last year to $8 billion. That's as much as Facebook (FB) collected but Alibaba is growing faster. Expenses are relatively low because it doesn't keep inventory, which is why it's operating margin is 50% compared to 28% for Google (GOOG) and 37% for Facebook. Alibaba also has plays in cloud computing, facilitating global wholesale commerce through Alibaba.com and online payments through Alipay.

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3. Investors could have concerns. One possible concern: price. Alibaba is valued at the high-end of estimates at $250 billion (the low-end estimate is $136 billion and the average is $168 billion), The Wall Street Journal reports. Its valuation at the high end is equivalent to 70 times last year's profits, which is more than twice the valuation of Google, trading at 30x last year's profits.

Investors may also have concerns about corporate governance. The company chose to list in the U.S. to keep its corporate structure as is, allowing Jack Ma, the chairman, and other executives the ability to control more than half of the board (Hong Kong regulations would have made that difficult). Meanwhile, Alibaba could feel the impact of rising competition from Chinese e-commerce rivals like Tencent Holdings (TCEHY).