At Revelry, we use BDD for all members of the team — and yes, that team includes our clients — so that everyone is clear about the intended user experience in the final product. Revelry’s flavor of BDD is a process for describing software features that is biased toward user’s actions and the results of those actions.
We can lose or gain users as a result of design changes. Terrifyingly, we can lose money due to bad UX design. So you can see how crucial it is to make the right UX decision.