On mobile ,3rd party cookies are not allowed. Any idea how does DSP and DMP work to identify user data?
Like what I have mentioned in another questions:
Usually u will place a DMP container tag on the page (well, there are other ways as well, I only list one of the standard approaches), where the first request sent is to hit the DMP and the response is DMP id plus a bunch of redirects from the partners (DSP's pixel link could be one of them. Actually if u are using Bluekai,these seats are biddable through their data marketplace). Then the browser will hit all these redirects with the DMP id. So DSP knows the DMP id to its own id mapping. The responses of these redirects return each unique id of these partners, so DMP can store the mappings as well. A simplified explanination could be found at http://www.adopsinsider.com/online-ad-measurement-tracking/data-management-platforms/syncing-online-data-to-a-data-management-platform/
The param passed by http GET or POST is usually cookie ids, where the actual data syn is usually carried out through real time or more often batch download server to server communication.
Hope it helps.