Consumers Spending Less Time on Websites

Google recently released their first summary report based on two years of anonymous web statistics gathered from hundreds of thousands of websites that opted into their anonymous data sharing pool. The results of this reports are quite interesting, and show a marked decrease in the amount of time the average consumer spends on each website.
In the United States, for example, people are spending an average of 6 minutes and 6 seconds on each website they visit, which is down by 10 seconds from a year ago. Japan’s change is much larger, with visitors spending 2 minutes and 59 seconds less on average on each website. That’s quite a large decrease in the amount of time people spend on individual websites!
While the report doesn’t analyse the possible reasons behind this shift, it is my belief that consumers in the developed world are much more demanding when it comes to what they want to experience from a website, and it’s becoming harder to keep their attention. Web developers need to focus on keeping their content relevant and immediately accessible, as our attention spans are shrinking.
As a quick addendum, consumers in developing nations (such as China and Brazil) are spending slightly more time on the average websites than they did a year ago. Is this because more and more consumers in these countries are discovering the web, or is this a cultural difference?