Amazon's ad business grew 19% in first quarter, topping estimates
1. Amazon's online ad revenue increased 19%, reaching $13.92 billion. 2. First-quarter total sales surpassed estimates at $155.67 billion. 3. Amazon is now the third-largest player in global digital advertising. 4. Economic tensions may impact Amazon's ad unit amid trade issues. 5. Competitors report solid earnings despite warnings of potential future headwinds.