Do recommendations need to contain social information to change behaviour in allocation and risk tasks? We conducted two online experiments involving 1280 participants to compare the behavioural influence of recommendations based on normatively relevant information with that of recommendations that were transparently random. Although social recommendations generally shifted choices towards the recommended option, consistent with previous studies on norm compliance, their effects were statistically indistinguishable from those of random recommendations. This finding challenges the notion that norm compliance is the sole mechanism through which social recommendations exert their influence. In a follow-up study with 481 participants, we investigated four additional channels. Our results suggest that recommendations do not act as reminders of existing normative knowledge, but we find evidence partially consistent with recommendation following in order to deflect responsibility, because of an anchoring effect, and because of a social norm to follow recommendations.