Planck differential number counts at 857 GHz, normalised to the Euclidean (i.e. S^2.5dN/dS). Planck counts: total (black filled circles); dusty galaxies (red circles). Models: Bethermin et al. (2011) (long red dashes – dusty); Serjeant & Harrison (2005) (short green dashes – dusty); Rahmati & van Der Werf (2011) (black dash-dot-dot-dot line). Other: Lagache et al. (2004); Negrello et al. (2007); Rowan-Robinson (2009); Valiante et al. (2009); Pearson & Khan (2009); Franceschini et al. (2010); Lacey et al. (2010); Wilman et al. (2010).