Defaults may not directly get people to behave as intended, such as saving more, eating healthy food or donating to charity. Rather, defaults often only put people on the 'right' path, such as joining a savings plan, buying healthy food or pledging money to charity. This an issue because getting more people to take those first steps does not necessarily motivate them to go on with further steps. Indeed, the default does little to help them understand the benefit of doing so. This can greatly reduce the impact of the default. We test this idea in a charitable giving experiment where people first can promise to give to charity ('pledge') and then can go on to donate. We find that participants pledge more often when that is the default, but those who pledge in that case are less likely to take further steps to donate than those who pledge when pledging is against the default. We interpret this in terms of motivation and transaction costs. Some people pledge only to avoid the psychological costs of going against the default. Those people are closest to indifference between donating or not and are therefore less motivated to go on to donate. We also show that the intrinsic motivation of pledgers is lower when pledging is the default and that making pledges the default does not change attitudes to charities.