Microsoft and Google presented the results of their user performance tests, and Brady Forrest at O’Reilly has a nice synopsis:

Here are Brutlag’s and Schurman’s final points:

• “Speed matters” is not just lip service
• Delays under half a second impact business metrics
• The cost of delay increases over time and persists
• Use progressive rendering
• Number of bytes in response is less important than what they are and when they are sent

These are pretty consistent with the conclusions we’ve already had, and corresponds pretty closely with the talk I gave up in Halifax last month, but it’s great to have some metrics attached.