We report threshold public good experiments in which group members not only need to be individually willing to contribute enough to provide the public good but also have to agree with each other on what every group members should contribute. We find strong support to the hypothesis that full agreement increases successful provision, although it takes a few repetitions before group members can successfully coordinate. This is consistent with our theoretical results that full agreement works because it increases criticality of each individual decision. The existence of a focal point makes it possible for the group members to successfully coordinate.