Come to think of it, every customer walkin (or customer engagement with some touch point) is actually a potential value opportunity. I don’t just mean it in terms of what he or she ‘needs to’ purchase but also what he or she ‘could have’ purchased.
So, when this walkin (or engagement) doesn’t achieve the full potential of that ‘could have’, in effect you are letting value walk out of your store (or touch point).
Perhaps this value can be potentially mapped in a two dimensional matrix with engagements on a side and value achieved on another. Such matrix could help us ideate on value retention and maximization with a unique perspective.