This screencast addresses a question in the Infusionsoft forums asking if it is possible to perform an action, like adding a tag, when someone opens an Infusionsoft email. Although not perfect, the video gives you a solution. The steps are:
1. In your email template, put an <img> tag in an html snippet and instead of using an image file as the src, use a script.
2. The script should do two things: perform any required actions you want as a result of the email being “opened”, e.g. applying a tag; and serve an invisible 1 pixel image to the email template.
The concept of an email open is pretty flawed. Accordingly, this method has many limitations. The biggest one is that it really only works for broadcast emails, not individual emails.
There is a non-API way to do this (credit: Tyler Garns), that replaces the script URL with a link to an automation link. My preference is a script, mainly because I have more control, since the execution occurs outside of Infusionsoft.
That is, however, a personal preference.
Infusionsoft obviously tracks opens in the contact record. So the only reason you would do this would be to trigger some action. So I am curious, what would be a business use case for being able to apply a tag or some other action? How would you use this?