The 2020 mobile advertising landscape is defined by a stark divergence in performance metrics across creative formats, operating systems, and geographic regions. While banner ads remain the most cost-effective entry point for driving initial installs, native and video formats demonstrate superior efficacy in securing high-value, deep-funnel actions such as in-app purchases. Native ads, in particular, achieve conversion rates as high as 52.8%, signaling their importance for long-term user retention. However, these performance gains come at a premium on iOS, where costs consistently dwarf those on Android. For instance, the cost of securing an in-app purchase through native ads on iOS reaches $218.09, nearly triple the $73.62 required on Android. Geographically, North America persists as the most expensive market for user acquisition across all formats, while the LATAM and APAC regions offer significantly more accessible pricing for advertisers. Seasonal trends also influence these costs, with install expenses typically peaking during the summer months. To navigate these fluctuations, successful campaigns increasingly rely on iterative A/B testing and dynamic creative strategies. Case studies from major brands like Credit Karma and Groupon illustrate that disciplined testing can yield lifts in click-to-install rates exceeding 120%, underscoring the necessity of a data-driven approach to creative optimization. The industry is shifting toward a performance-based, cost-per-action model that prioritizes post-install revenue events over simple downloads. By leveraging machine learning and focusing on single-deal creative strategies, advertisers can better align their spending with actual user value. Ultimately, the data suggests that while the cost of acquisition is rising, particularly on premium platforms and in mature markets, the integration of dynamic product ads and rigorous testing frameworks remains the most effective path toward achieving sustainable return on ad spend.