Holding the purse strings gives you the power to act, decide, veto, choose, etc. You can step in at the last minute and decide to call the whole thing off.
Obviously, information is shared and discussed during complex decision-making processes. Sales teams prepare sales messages, kits, demonstrations, etc. The potential client holds internal meetings, they look at the literature and compare solutions, they meet the sales force. There may be a pilot study, the results of which are shared and analyzed. There are additional internal meetings, during which the outcome of the pilot study is discussed : return on investment, adoption rate, customer satisfaction, etc.
And yet, sometimes someone suddenly comes out and stops the whole process, meaning the whole thing is dropped. This someone may or may not have had access to the information during the evaluation period.