"This location information may be used by itself, aggregated, or combined with mobile identifiers (such as IDFAs and Android IDs), and shared with third parties, for purposes related to advertising, attribution (e.g., measuring ad performance) analytics and research. Similarly, third-party advertising companies may provide us with pixel tags (also called "clear gifs" or "beacons") to help manage and optimize online advertising."
The combination of advertising IDs (IDFAs, Android IDs), cookies, pixel tags/beacons, and location data across multiple ad networks enables cross-service tracking and profiling of users across apps and websites.