Call tracking data can be leveraged in 3 ways to improve ARPA for marketplaces: 1. Gather basic call data like talk time, lead volumes, and call handling to understand advertising performance. 2. Collect more detailed data through call recording, transcription, and AI analysis to provide insights into properties of interest, advertising strategies, and outcomes. 3. Monetize the collected data by creating customized call analytics packages to sell to agencies and private sellers, generating new revenue streams for the marketplace.