The paper argues that institutional accounts are useful but incomplete in providing an understanding the dynamics of the completion of the internal market. This is because they do not leave enough room for ideas and norms, which have been central to the gambling story. The paper argues that prevailing norms about gambling, which have associated it with inter alia charities, criminal activity, public health and public order, have worked to mitigate the desire for a single market and arguments about the efficiency of market liberalization. Gambling is a useful case to illustrate that there is ambivalence about market building that tries to reconcile possible efficiency gains that come with enhanced competition with an aversion to promoting risk.