Ipsos-Social-Media-Purchase-Influence-US-v-World-Aug201335% of online consumers across 24 countries claim to have ever purchased a product or service based mostly on an ad they saw on a social media site, details Ipsos Open Thinking Exchange in new survey data. But that figure drops to just 18% in the US. Similarly, US respondents were about half as likely as the average global respondent to report having ever purchased a product or service based mostly on a posting they saw on a social media site (16% vs. 31%).