Per Sizmek Support: 1x1 Tracking pixels can only support 1 instance of 3rd party tracking event. 1 for impression and 1 for click tracker.
I would like to submit a product request to support multiple third party event tracking for 1x1 trackers, similar to what they support for ad creatives.
Who would benefit from this? Advertisers who are using multiple sources for impression and analytics tracking to be able to traffick one pixel to publisher/network/DSP, but fire multiple pixels in the backend via a JS 1x1 impression tracker.