The most popular websites that sell smartphone adhesive in the United States include Amazon, eBay, and Newegg. These platforms are widely recognized for their extensive product offerings and reliable customer service. Amazon, in particular, stands out due to its vast inventory and competitive pricing, with over 1.5 million adhesive-related products listed as of 2021. eBay offers a diverse range of sellers, allowing consumers to compare prices and read reviews, while Newegg is known for its tech-centric focus, catering to both hobbyists and professionals.

The popularity of these websites can be attributed to several factors. Firstly, Amazon's vast customer base and robust search algorithm make it easy for users to find the specific type of adhesive they need. According to a report by Statista, Amazon's U.S. e-commerce sales reached $233.5 billion in 2020, highlighting its dominance in the online retail market. eBay's user-friendly interface and seller diversity contribute to its appeal, as it provides a wide range of options and competitive pricing. Newegg's focus on technology products, including smartphone accessories, has made it a go-to destination for tech enthusiasts and professionals alike.

Moreover, the convenience of online shopping is a significant driver behind the popularity of these websites. Consumers can browse and purchase adhesives from the comfort of their homes, often with free shipping options and fast delivery times. According to a study by Adobe, 61% of online shoppers in the U.S. cited convenience as the top reason for purchasing online, further solidifying the importance of online retailers in the smartphone adhesive market.