The Computers That Buy Online Ad Space Automatically Stop When There's A National Tragedy

There are sharp drops in online advertising bid activity during times of widespread negative news reporting, according to a report from Casale Media's Index Exchange.

The chart below shows the number of bids per impression plummeting on the days of the Boston Marathon bombing and the death of actor James Gandolfini:

When the news is bad, "big national brands go away," Andrew Casale, VP Strategy of Casale Media, told Business Insider. These companies use negative targeting to automatically determine which pages are carrying keywords they do not want their brands appearing next to.

The Boston bombing is an obvious one for the keyword bots. For situations like the death of a beloved actor, technicians can add his name and related words to the system.

So next time something bad happens, expect to see fewer ads with your headlines.