What are email tracking pixels, and why are they used?

Online security has become a hot topic in recent years, following a series of scandals surrounding data breaches and information harvesting.

Yet many of us have significant blind spots to the ways in which we’re being monitored and tracked.

It’s easy to overlook the fact that emails can be used to track user activity just as much as webpages.

And one of the methods used for this covert reconnaissance involves email tracking pixels.

Despite comprising a single on-page pixel, these diminutive tracking tools reveal a great deal about our online activities.

Track and field

As the name suggests, email tracking pixels are solitary pixels embedded in either the header, footer or body of an email, usually as a GIF or PNG file.

Typically the same colour as their surroundings, there is no way for users to identify their presence.

However, these pixels monitor everything from whether an email is deleted without being opened to how often it’s viewed, on which devices, and where they’re located.

Information is fed back to the sender, helping to shape future campaigns.

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For instance, if marketing email A achieves a 50 per cent open rate where email B achieves 25 per cent, future email campaigns will draw more inspiration from A than B.

If iPhone owners engage strongly with email C but Android owners seem to spend more time reading email D, this will also affect the content these handset owners receive in future.

The threat is real

According to recent research by messaging service Hey, two-thirds of emails delivered to inboxes include email tracking pixels.

That’s not even taking into consideration spam messages which get blocked by filters.

Indeed, if you’ve ever received a spam email that contained nonsense text and nothing else, it probably had a tracking pixel in it.

Spammers are always trying to learn what will bypass the Bayesian filters designed to sieve out their content, and tracking pixels monitor the percentage of mail that’s opened.

Since spammers make a profit even if only 0.000008 per cent of email recipients respond, it’s worthwhile embedding email tracking pixels in every message to see what happens.

Some of the UK’s biggest brands use tracking pixels, so this is far more than a niche activity, or something practiced by disreputable businesses.

Alarmingly, it’s possible to link pixel data with browser cookies, effectively connecting an email address and a web browsing history.

This could hugely increase the amount of personal information being cultivated by marketing companies, which can be used pretty much however they wish, for as long as they like.

Can I stop them?

There’s not much you can do to stem the tide, though third-party companies will flag tracking emails via plugins or apps.

You could block all email images from displaying, view messages as plain text, or simply minimise email communications in favour of post and phone contact.

It’s possible companies will begin removing tracking pixels as public awareness of this tactic grows.

The Information Commissioner’s Office is in the process of removing pixels from future email correspondence after their use was highlighted by the BBC.

It’s presently a legal requirement for the use of tracking pixels to be publicised, but any acknowledgement is usually buried in swathes of T&C documentation few people will read.

Until legislators make accepting tracking pixels as explicit as cookie acceptance is under GDPR laws, this phenomenon is likely to increase rather than decline.