1. The document examines the hidden costs of mobile advertising for both advertisers and users by analyzing a large dataset of 1270 mobile users over 12 months. 2. It finds that while advertisers pay an average of $0.00071 per ad impression, users bear costs of around $0.0022 per ad in bandwidth and privacy losses that are 3 times higher than what advertisers pay. 3. The costs to users include ads and analytics comprising 19% of data requests, 8.2% of download volume, and over 9% of smartphone power consumption, as well as loss of online anonymity through cookie synchronization tracking users.