This article reports the results of a study of permission-based advertising via mobile phones. The study, part of the proof of concept for a UK startup, specifically explored the effectiveness of SMS text messaging as an advertising medium for reaching young adults. The results suggest that, with the right execution, the mobile channel has the potential to benefit both advertisers and consumers. The findings also include some suggestions about when and how to use this emerging new medium. Although confined to SMS text messaging in the UK, the results are also likely to be relevant to other countries, and to more advanced mobile communication technologies as these are rolled out. © 2002 John Wiley & Sons, Inc. and Direct Marketing Educational Foundation, Inc.