Aim Online advertising is a new frontier in research recruitment and Google Adwords (GA) is one method of online advertising. Only a handful of studies, however, have described its cost and effectiveness and none have focused on older adults. The aim of this paper is to describe a GA campaign used to recruit family carers of people with dementia and provide insight for researchers planning to use GA to recruit other older adults. Method A GA campaign was used to recruit family carers of people with dementia to a cross-sectional study of wellbeing. Results The ads were viewed more than 450,000 times in a six-week period, but only 49 surveys were completed, at a cost of $122 per survey. Conclusion GA has promise, but much remains to be understood about how to maximize its potential in ageing research. Recommendations for the design of future GA campaigns are provided.