Pixel Envy

Written by Nick Heer.

Defeating Spy Pixel Workarounds in Email

Ajay Goel of GMass, an extension for Google Chrome that helps people send more spam email (via David Heinemeier Hansson):

Starting today, the open tracking pixel we insert into your emails to track opens will look different. They will now be non-parameterized, encrypted URLs that are very, very difficult for pixel-blockers to detect.

Ever since email marketers invented a way to track whether someone opens an email, counter measures have been trying to block the ability to tell whether an email has been opened. Open tracking works by inserting an image tag into the email, where the image URL is unique to each recipient. If that particular image is downloaded by the email client, then the marketer knows that that particular recipient opened the email. It’s a trick email marketers and cold emailers have used ever since emails were allowed to contain HTML.

I know it shouldn’t, but stuff like this winds me up. Goel seems very proud of building a product that does not respect users’ wishes. If I were so unethical, I would not want to draw attention to how much of an asshole I am in a smug blog post.

Most email clients allow you to switch off all images, even if they don’t have a fancy tracker-specific blocker like Hey or, somewhat ironically, Superhuman. For what it’s worth, I recommend doing so. Many email trackers are not simple read receipts; they can report far more information about you, as Goel’s blog post illustrates.