Customers and you review the reasons why they pursued or abandoned projects with similar goals in the past. This analysis provides both of you with reality checks on whether their goals are achievable and the extent of their interest levels. You should not focus on why they did or did not buy a product or you will end up in the "What did they do for you?'' trap. If they deem goals worthwhile, they want to make sure they repeat their formulas for successes while avoiding the mistakes of the past.
This filter also tells you which role you are working with. Gatekeepers usually do not know why previous attempts to achieve specific goals failed; advocates and FDMs do. Information on failed attempts also furnishes you with the type of cost justifications and measurable benefits customers need to say yes.