Pascale has a post up giving some tips for avoiding distractions–many of them from the Internet–while trying to get work done. These are probably perfectly good ideas if you are seeking to increase your sustained focus at work.
However, she also refers to a published article announcing that workplace distractions, those that take us off-task, cost our economy over $10,000 per worker per year.
Such estimates of “lost workplace productivity”–such as the handwringing every year during March Madness about “billions of dollars of lost productivity due to bracket pools”–are a complete lie. This is because they assume that every minute of time that a worker dickes around on the ESPN Web site subtracts an entire minute of time from the total amount of time spent working during a day *and* that work output over the course of a day (or week or whatever) is a linear function of time spent working during that interval.
With regard to the first assumption, it is obviously the case that different distractions can also displace one another, and not just displace work. With regard to the second assumption, the marginal output from a given unit of time spent working decreases as the amount of time spent working increases (once you reach some minimum threshold).
The result is that these estimates of lost productivity are always grossly overblown.