This technical disclosure outlines how cookies and various online identifiers, such as IP addresses and device specifications, are utilized to recognize users across apps and websites. By collecting data including browser types, screen sizes, and interaction history, services can build detailed user profiles to personalize both advertising and non-advertising content. These profiles facilitate targeted marketing based on interests and personal aspects, while also helping to adapt the order of content shown to users. Furthermore, data collection serves to measure advertising effectiveness, prevent fraudulent activities like bot clicks, and ensure technical compatibility. The text notes that user choices are communicated via digital signals to respect privacy preferences. Additionally, services may combine data from multiple sources or link devices within a household to refine audience identification and improve overall product functionality and security.