1. Ease of Use & Navigation
   A study done by Nielsen Norman Group found that users expect clear, simple navigation & easy-to-use interfaces (Nielsen & Tahir, 2002). Keep the layout clean & ensure that users can quickly find what they need.
   
2. Mobile Friendly Design
   According to Statista, more than 50% of all online traffic comes from mobile devices making a mobile-first design a priority (Statista, 2021). Responsive design that adapts to various screen sizes is essential for a seamless user experience.
   
3. Fast Load Times
   A Google study found that 53% of mobile users abandon a site if it takes longer than 3 seconds to load (Google, 2016). Optimize images, minimize HTTP requests, and use content delivery networks to improve load times.
   
4. Trustworthy & Secure
   Baymard Institute's research found that 17% of US online shoppers abandoned their carts due to concerns about payment security (Baymard Institute, 2021). Implement SSL certificates, display security badges, and follow best practices for secure transactions.
   
5. Product Images & Descriptions
   Multiple studies have shown the importance of high-quality product images and detailed descriptions for online sales (e.g., Chatterjee, 2001). Use professional photography, provide zoom functionality, and offer accurate, well-written product information.
   
6. Optimized Checkout Process
   The Baymard Institute found that the average cart abandonment rate is around 70%, with a complicated checkout process being a significant contributing factor (Baymard Institute, 2021). Simplify the checkout process by reducing steps, offering guest checkout options, and providing multiple payment methods.
   
7. Personalization & AI-Driven Recommendations
   Research has shown that personalized recommendations can significantly increase conversion rates and customer engagement (e.g., Tam & Ho, 2006). Implement personalization features using AI and machine learning to show relevant products and offers to individual users.
   
8. Reviews & Ratings
   A study by PowerReviews found that 97% of consumers consult product reviews before making a purchase (PowerReviews, 2017). Display customer reviews and ratings prominently to build trust and provide valuable information to potential buyers.
   
9. Shipping & Return Policies
   A UPS study found that 66% of online shoppers check the return policy before making a purchase (UPS, 2016). Clearly communicate shipping costs, delivery times, and return policies to help customers make informed decisions.
   
10. Search Functionality
    An Econsultancy study found that 30% of eCommerce site visitors use the site search function (Econsultancy, 2014). Implement an efficient, user-friendly search feature with autocomplete, filtering, and sorting options to help users find products easily.

Sources

• Nielsen, J., & Tahir, M. (2002). Homepage Usability: 50 Websites Deconstructed. New Riders.
• Statista. (2021). Share of mobile internet traffic in global regions 2021.
• Google. (2016). Find Out How You Stack Up to New Industry Benchmarks for Mobile Page Speed.
• Baymard Institute. (2021). Cart Abandonment Rate Statistics.
• Chatterjee, P. (2001). Online reviews: Do consumers use them? Advances in Consumer Research, 28(1), 129-133.
• Tam, K. Y., & Ho, S. Y. (2006). Understanding the impact of web personalization on user information processing and decision outcomes. MIS Quarterly, 865-890.
• PowerReviews. (2017). The Growing Power of Reviews: How Online Reviews Influence Offline Sales.
• UPS. (2016). UPS Pulse of the Online Shopper: Tech-savvy shoppers transforming retail.
• Econsultancy. (2014). The Future of Site Search.

TL;DR

Designing a great eCommerce website involves considering factors such as ease of use, mobile-first design, fast load times, security, high-quality product images and descriptions, streamlined checkout, personalization and AI-driven recommendations, customer reviews and ratings, clear shipping and return policies, and effective search functionality. These factors are backed by research and expert opinions from sources such as Nielsen Norman Group, Statista, Google, Baymard Institute, and more.