The recipe for spam

It just keeps piling up. No matter how much email spam you get rid of, more of its slimy chunks always find their way to your inbox. Even though it’s so common, it’s a little mysterious. Who sends it? Does anyone actually buy the stuff in spam messages? What’s the best way to keep spam from oozing into your email? Much like both the processed meat and the Monty Python sketch from which it takes its name, the world of spam is weird.

Spam-spewing zombies

Depending on your point of view, spam could be sent by just a few rogues or millions of zombies. Even though Spamhaus, a charity devoted to tracking spam, estimates that more than 90% of all the emails sent in the world are spam, amounting to billions every day, there are probably only around 200 people responsible for it. That’s a tiny number of people for such a huge glut of emails. Those few people don’t send out all those messages themselves though, and that’s where an army of zombies comes in.

The few spam kingpins need lots of others to do the work, so a lot of spam actually gets sent by regular people all around the world, completely unaware they’re doing it. Their computers spew out spam on the sly because of little programs called malware running on their machines. Often malware comes tucked into attachments on other spam emails, into downloads on peer-to-peer networks, or even as part of a website. It secretly installs itself and gets to work in the background, turning someone’s friendly computer into a zombie under its control, using their internet connection to send out thousands of spam emails with its owner none the wiser.

The maths of being dumb

Ever read through a spam email advert? They might be lots of things – saucy, badly spelled, offensive, even criminal – but tempting probably isn’t one of them. If they’re so bad then why does spam exist at all? Isn’t the point of adverts to make people buy things? Get ready for this: it turns out that spam actually works. Not many people fall for spam, but not many have to. Because it’s free for the spammers to send their zombie-powered emails, even if fewer than one in a million people is head-slappingly brainless enough to click on a spam advert for an expensive designer watch, the spammer still makes money. When you’re sending out billions of emails every day those few people still add up to a lot. It makes you wonder if the same dumb people buy all the spam merchandise in the world. Maybe every city has one person whose house is overflowing with fake watches and pills from junk emails.

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