By The Numbers:

Business Top 40

The Keynote Business 40 Internet Performance Index (KB40) measures the average download time for the home pages of 40 important US-based business Web sites.

Page load performance is key to the “stickiness” of every Web site. In these results from Keynote’s weekly Business Top 40 Index, Facebook and Yahoo! performed within the two seconds that most users consider an acceptable page load time. AOL was a bit over the threshold, and MSN took nearly three seconds. Given the rich content they are loading, these times should be acceptable for the majority of visitors.