Verily, you could not make this up. A headline saying that Microsoft had made its first-ever loss caught my eye. I assumed it must be a mistake: Microsoft doesn’t make losses for the simple reason that it has a licence to print money. It’s called Windows+Office. But then it turns out that Microsoft blew $6.2bn a while back on an advertising company which has now turned out to be worthless. What always amuses me about tech company valuations is how solemn are the assurances from men in suits that the valuation they have arrived at by consulting the entrails of a goat is in fact a perfectly rational assessment of the asset’s value. I am sure that that $6.2bn valuation was likewise quality-assured by the same clowns.

Microsoft has written down the value of an online advertising firm it bought five years ago by $6.2bn (£4bn).

Microsoft bought Aquantive for $6.3bn in cash in an attempt to catch rival Google in the race to increase revenues from search-related advertising.

The writedown effectively wipes out the acquisition’s value, although there was little impact on Microsoft’s shares in after-hours trading on Monday.

The purchase of Aquantive in 2007 was then Microsoft’s biggest acquisition.

It has since been eclipsed by the company’s $8.5bn purchase of internet phone service Skype last year.

Microsoft said in a statement on Monday that “the acquisition did not accelerate growth to the degree anticipated, contributing to the writedown”.