The most popular website that sells furniture in the United States is Amazon. Amazon offers a vast selection of furniture items from various brands and manufacturers, making it a go-to platform for consumers looking for a wide range of options. According to a report by Statista, Amazon held a 48.8% market share of online furniture sales in the U.S. in 2020, far surpassing its competitors. This dominance can be attributed to several factors, including the company's extensive product range, competitive pricing, and user-friendly interface.

Amazon's furniture offerings span across different categories, including bedroom sets, dining room furniture, living room sets, outdoor furniture, and more. The platform also features a variety of furniture styles, from modern to traditional, catering to diverse tastes and preferences. Additionally, Amazon's Prime membership program provides customers with fast and free shipping, further enhancing the convenience of purchasing furniture online.

One of the key reasons for Amazon's success in the furniture market is its ability to leverage its vast customer base and data analytics. By analyzing customer preferences and purchase history, Amazon can recommend personalized furniture options, making the shopping experience more efficient and tailored to individual needs. Moreover, Amazon's customer reviews and ratings system allows potential buyers to make informed decisions based on the experiences of others.

Another factor contributing to Amazon's furniture market dominance is its strategic partnerships with well-known furniture brands. These collaborations enable Amazon to offer a wide range of high-quality products at competitive prices. For instance, Amazon has partnered with brands like IKEA, Wayfair, and West Elm, which are renowned for their furniture products.

Furthermore, Amazon's Prime Day event, an annual sale that offers significant discounts on a variety of products, including furniture, has become a major shopping event for many consumers. This event not only drives sales but also reinforces Amazon's position as a leading furniture retailer.

In conclusion, Amazon is the top website that sells furniture in the United States, thanks to its extensive product range, competitive pricing, user-friendly interface, and strategic partnerships with well-known brands. The company's ability to leverage customer data and provide personalized recommendations has also played a crucial role in its success. With a market share of 48.8% in 2020, Amazon has established itself as a dominant player in the online furniture market.