Internet advertising: getting message over Do you want advertisers keeping track of you, the better to sell you things? What sort of anti-capitalist eccentric would not? Despite this, Microsoft has recently decided to make "do not track" the default setting on its next-generation web browser. Unless its user specifies otherwise, the software will send a message to any website visited, requesting that the site not record the user's movements and tailor online ads accordingly. Advertising industry groups are unenthusiastic. They complain that Microsoft's policy may "undercut thriving business models, and reduce the availability [of] Internet products" and lead to "untargeted, irrelevant online advertising." These are hilariously bad arguments. Undercutting thriving business models is exactly what technology companies should do. Microsoft's job is not to make sure that rival software designers and internet publishers make money; it is to make its own software as appealing as possible. Microsoft sells internet ads itself, but it knows where the bread is buttered: it sold $42bn worth of operating systems and office software over the past year, which is about how much internet display advertising was sold worldwide in 2011. And the claim that untargeted advertising imposes a cost assumes that what consumers do not buy must hurt them. There is a gap between the time we devote to the internet and the amount of advertising revenue it attracts, relative to other media. Research from Kleiner Perkins suggests that closing this gap would generate another $20bn in internet advertising revenue in the US alone. But the issue may not be that ad buyers are behind the times, or that ad design has not adjusted to the new medium. Instead, it may be that of all media, the internet maximises choice, and when given choice, people avoid advertising.