How The Hell Did Google Know That About Me?

Stalking, spying, and stealing contacts. Yeong Sassall investigates the scary world of online marketing.

- Yeong Sassall

A few weeks ago, I went looking for a new pair of jeans online. After browsing a few sites, I couldn’t make up my mind and gave up. So far, so indecisive. But then a funny thing happened. Over the next week, I started to notice online ads for that exact pair of jeans everywhere—when I read the news, as I scrolled through blogs... even while shopping on other websites.

I didn’t need more temptation to shop, but what could I do? Stalkerish Internet ads are more ubiquitous than a Miley Cyrus meme. Still if, like me, you’re starting to wonder if anything is private anymore, read on to find out exactly how you can stop leaving your electronic footprint all over the web.

The How And The Why

You know the square or banner adverts that sit at the top of every webpage? It’s accurate to say that they know you. Commonly known as targeting or remarketing ads, “they target your interests based on your web history and network activity,” explains Dali Kaafar, Principal Researcher and Research Leader at IT research centre NICTA, Australia.

But how exactly do they work? Well, there are a few different methods, yet most commonly they use cookies to collect your data. Cookies, are small, unique files that are saved to your computer whenever you visit a website—they help that site recognise you if you’ve been there before. But often these cookies stay on your computer, tracking you long after you’ve left the site. Then, clever advertising networks use that information to try to figure out exactly the sort of adverts that are likely to appeal to you.