Speed Matters

...Our experiments demonstrate that slowing down the search results page by 100 to 400 ms has a measurable impact on the number of searches per user of -0.2% to -0.6%... Google

...40 percent of shoppers will wait no more than three seconds before abandoning a retail or travel site... Akamai

...Speed was clearly the most important factor influencing the average participant's preference about the product prototype... WebSiteOptimization.com