Official comment
ONTRAPORT tracks landing pages, but not pop up lightbox forms until they are filled out and submitted. One method to track when a form pops up is to use the HTML block positioned at the top of the form and insert a landing page in a single pixel iframe. Wrap this in a div that is hidden and when the form pops up, the landing page visit is recorded. You can then use that landing page as a proxy for the form popping up, and determine the number of people who simply close the pop up without filling out the form.
Create the special use landing page first and publish it on one of the ONTRAPORT URLs. Use a secure URL if your lightbox form will be on a secure domain. Copy the domain of the published landing page for use in the ONTRAform.
In the HTML block, use code such as:
<div style="display: none;">
<iframe src="http://the-url-for-your-special-use-landing-page.ontraport" width="1" height="1" style="border: none;"></iframe>
</div>
When testing, allow up to 15 minutes for the page visit tracking to be added to the Contact Record. Tracking information is not written to the Contact Record as quickly as other information.