On Jakob Nielsen and taking a pee

I’m usually a fan of Jakob Nielsen‘s analysis. But this seems barmy: ‘the cost of ownership for “free” software can easily exceed $1M/year in an enterprise setting.’
His starting point is reasonable – that ‘text-box ads accounted for 0.3% of the users’ gaze duration’ in recent testing. This becomes 11 seconds per day, or 44 minutes per year; and extrapolating on the basis of average salaries, and allocating a percentage of overheads, and factoring in the average time spent on the average website – we get a total figure of $1.2 million per year for a company of 10,000 people.
All this from a calculation of ’11 seconds per day’. I probably spend 11 seconds per day coughing and/or sneezing. I certainly spend longer than 11 seconds per day glancing out the window, or going to the toilet. I don’t think either is creating a productivity crisis. Or perhaps I’m being naive: if I attach myself to a catheter, I don’t need to leave my desk to take a pee, and we even save on the cost of cleaning a urinal.
Text-box ads have their place. Paid search placement shows that a company is prepared to put its money where its mouth is; and the process dictates that it has explicitly identified appropriate keywords. Arguably then, paid results may be more relevant than natural search, and more valuable as a navigation device. You can’t just dismiss them as a hindrance like this.