Google knows everything about you. Your shoe size, your marital status, whether you have children, how many and their ages. It knows your age, how you spend your free time, what you do for a living and your political leaning.
Google needs to know everything about you. If it didn’t you probably wouldn’t use it as much because search results would not be anywhere near as relevant and, most importantly, it would not be able to target specific advertising to you, which is Google’s main source of income and, arguably, its Achilles’ heel.
In his book The Filter Bubble, Eli Pariser offers a bleak vision of how the internet is evolving, with ever greater personalisation which results in bubbles of information that only show us what the web thinks we want to see1.
This is why, when you search for cheap holidays online, you are then followed all over the internet by ads from companies trying to sell you car hire, affordable hotel rooms and travel insurance.
Pariser’s filter bubble has greater, darker repercussions than just being followed by annoying ads. In order to service this quest for ever greater personalisation, companies have sprung up that buy and sell information about you in automated transactions that take place in less than a second. This way Nike knows when you are most likely to buy some trainers and can bombard you with highly targeted advertising.