DMP Pixel

Data-management platform (DMP) partners that it would impose new restrictions on pixels fired by campaigns that run on the Google Display Network (GDN).

http://adtagmacros.com/2014/12/dmp-pixel.html

DMP means “Collecting impression-level data via cookies or other mechanisms for purposes of subsequent re-targeting, interest category categorization or syndication to other parties on Google Display Network inventory is prohibited,”.

What is DMP ??

DMP are is collaboration of many data suppliers .A Data Management Platform (DMP) is a technology platform that collects, stores, and packages the consumer data it receives from various Data Suppliers.Through database integration, DMPs will then make this information available to its various ad technology partners.

DMP which owns the demand-side platform (DSP) buying the impression are only allowed to track the user data.The ability to cap how many times a certain consumer sees an ad. 

This reduces media waste and lets [advertisers] reach more people at the optimum frequency rate.So a client buying inventory with multiple DSPs won’t have visibility into consumer activity around ads running through Google Display Network, limiting the ability to optimize how often an ad is shown.

Problem in DMP pixel

The problem with many banner ads is that they’re stuffed with too many tracking pixels.This bloat increases the possibility of audience data leakage, which many vendors believe is Google’s rationale for its regulatory tighteningReason behind this as per google is concerns for potential data leakage and pixel loading as reasons for the change.

DMPs are more than just being able to identify characteristics on the same user from multiple systems however.  DMPs offer profiling and segmentation technology that allows you to look at data from both directions.  

Impact on Users

You can certainly create audiences with rich characteristics that you know, but you can also use a DMP to figure out what a high performance audience has in common.

For More regarding cookie syncing  between DMP and DSP Source:Tom Chavez,Adexchanger