Constraints from tomographic peak counts compared to current galaxy cluster constraints, with contours giving the 1 and 2σ confidence limits. The violet shading represents constraints from the maxBCG cluster catalog, blue those from WMAP-5, and the yellow their combination; they have been adapted from Allen et al. (2011). The green contours give the tomographic peak-count constraints for a Euclid-like survey covering 15 000 square degrees.