Large companies such as Fortune 500 companies spend disproportional amount of their efforts on settling internal affairs. In a company with 2.2 million employees, such as Wal-Mart, the politics is the dominant force at play and any vendor selling to such behemoths must primarily excel at understanding internal balance of power and be master lobbyist.
One of the most powerful weapons used in internal battles is calling in higher authority, such as external consultants or state-of-the-art technology. In any complex affair, it's close to impossible to come with such a strong hand of arguments, that the battle would be decisively won. What happens usually in such cases is that two competing proposals each accrue a pile of arguments until a stalemate ensues. The normal reaction of large organizations in such cases is to do nothing as it's too painful for everybody involved to fight yet another battle. But if the change initiative is of strategic importance, the conflict must be resolved nonetheless. Resolution of conflicts in an organization always includes escalation of the problem to the higher authority, that is, a boss one level higher than everybody involved. Executives in a hierarchical organization are always disproportionally busy (fighting their own internal battles) so all they ever do is call somebody in and delegate the authority to resolve the situation either to internal agency tasked at resolving interdepartmental conflicts or external consultancy.
As is the case with any mediator the external agency can't really take sides, but all it can do is to change the domain of discourse. Software and other technological solutions are great way to change discourse without taking sides. Internal users rarely know the long-term effects of introducing a new technology, so if things are acceptable in the short run a substantial change can be introduced in the organization without a stiff resistance. If a software vendor can repeatedly introduce change in enterprises, it will quickly become a darling of every executive frustrated by rigidity of his or her organization. It's exactly this reason that has made SAP, Oracle, Salesforce, and other enterprise vendors so successful.