1. Customer satisfaction: Fast delivery meets the immediate expectations of customers who want their purchases quickly. Satisfied customers are more likely to become repeat buyers and recommend the online store to others, fostering customer loyalty.

2. Convenience: One of the primary benefits of online shopping is convenience. Fast delivery enhances this convenience by reducing the time between placing an order and receiving the product, making it a more efficient and attractive option compared to traditional brick-and-mortar shopping.

3. Competitive advantage: In the highly competitive world of e-commerce, fast delivery can be a differentiating factor for an online retailer. It can help a business stand out from its competitors and attract more customers.

4. Reduced cart abandonment: Long delivery times can lead to cart abandonment. When customers see that the estimated delivery time is too long, they might decide not to complete the purchase or look for the product elsewhere with quicker delivery options.

5. Meeting expectations: As online shopping has become increasingly popular, customers have come to expect faster delivery times. Failing to meet these expectations can lead to dissatisfaction and negative reviews.

6. Impulse purchases: Fast delivery can encourage impulse buying. When customers know that they will receive their products quickly, they are more likely to make unplanned purchases.

7. Seasonal demands: During peak seasons or holidays, fast delivery becomes even more critical. Timely deliveries are necessary to handle increased order volumes and ensure customers receive their purchases on time.

8. Minimizing returns: Prompt delivery can reduce the chances of customers returning products due to long waiting times or changing their minds.

9. Reputation and trust: Timely delivery builds trust and enhances the reputation of the online store. Positive reviews and word-of-mouth recommendations can boost the store's credibility.

10. Cost-effectiveness: While fast delivery might seem like an added expense, it can lead to cost savings in the long run. Efficient delivery processes can help minimize storage and handling costs, improve inventory turnover, and reduce the need for customer service support related to late deliveries.

Overall, fast delivery in online shopping is a critical factor that can significantly impact a business's success, customer satisfaction, and reputation in the market. Online retailers need to strike a balance between speed, cost, and efficiency to provide an optimal delivery experience for their customers.