Clients come in all sizes and descriptions. Some are a veritable fountain that continually spews ideas and changes. This may seem like an enviable situation, but don't overlook the need for convergence to a solution. Their behavior can cause the team to spend too much time on non-value-added work as they do their analysis of the scope implications and contribution to business value. A strategy to postpone some suggestions to the next version might work. Others don't seem to have any ideas to share.