What was the most important impact of Major League Baseball's Web site development efforts?

The most important impact of Major League Baseball's website development efforts lies in how it strengthened the relationship with customers and suppliers. By creating a robust online presence, MLB was able to directly engage with fans, providing real-time scores, news updates, merchandise sales, and ticketing options, thereby enhancing the overall fan experience. This direct line of communication fostered loyalty among fans, leading to increased attendance at games and heightened interest in the sport.

Additionally, the development of the website served as a platform for better coordination with suppliers, such as merchandise vendors and media partners, making it easier to manage inventories, logistics, and promotional efforts. By cultivating these relationships, MLB could more effectively merchandise its brand and content, ensuring that both fans and partners remained engaged and invested in the league's success.

While the other choices reflect benefits of the website, such as operational efficiency or strategic advantage, the connection with fans and suppliers is vital for sustained growth and relevance in a highly competitive entertainment landscape, thus making it the most significant impact.