Recruiting participants into cancer survivorship research remains a significant challenge. Few studies have tested and compared the relative use of non-clinical online recruitment methods, especially in samples of adult cancer survivors. This paper reports on the feasibility of recruiting a representative cohort of cancer survivors using online social media. Two hundred participants with cancer diagnosis within the past 12 months were recruited via social media (Facebook, Twitter and Reddit) into a longitudinal questionnaire study. Different methods of online recruitment proved to be more effective than others over time. Paid Facebook boosting, Reddit posts and Twitter advertisements placed by existing cancer charities proved most helpful in reaching our recruitment target (contributing 27%, 22% and 32%, respectively). Recruiting online achieved a more demographically and clinically representative sample for our study: our subject was younger, less heteronormative, including those with a range of clinical diagnoses, primary and recurrence illness, and patients who had both completed and were still receiving treatment. This was certainly not a quick method of sample recruitment but that could have been optimised by focussing only on the three most effective methods described earlier. While we found that online recruitment is significantly lower in cost than traditional recruitment methods, and can reduce some biases, there still remains the potential for some biases (e.g. excluding much older participants) and ethical/methodological issues (e.g. excluding those without access to Internet). We outline our recruitment strategy, retention rates and a cost breakdown in order to guide other researchers considering such methods for future research in cancer survivorship.