In a global population that exceeds 5 billion subscriptions, consumer product strategists recognize that smartphones are a niche today. Yet in the US and in some European countries, smartphone penetration is racing past 25% — smartphones are going mainstream, albeit at a varying pace across the globe. This report clarifies this phenomenon, leveraging Forrester's Technographics® segmentation and identifying factors influencing adoption rates. Consumer product strategists should anticipate the consequences of moving from a smartphone target audience of early adopters to one that is more mainstream.