Jet.com, the ambitious startup launched by CEO Marc Lore earlier this year, is certainly attracting plenty of attention. Based on data Jet.com provided, the company’s growing fast. It’s quickly become one of the bigger players in the US e-commerce market—number 4 by gross volume, it says—behind Amazon and eBay, and beating out established brands like Sears and Best Buy. Lore, who sold Quidsi and its Diapers.com and Soap.com sites to Amazon for $545 million, essentially wants to be the “Costco of the Internet.” Jet has raised $220 million in 3 rounds of financing thus far, bringing in major investors like Bain Capital Ventures, Citi Ventures, Google Ventures, Goldman Sachs, and Alibaba. It recently shifted its business model – moving away from charging customers a $50/year subscription fee and opting to take a small slice from each transaction instead. Competing with the scale and logistical prowess of Amazon will be a Herculean task for the New Jersey-based company.