These timeless quotes are benchmarks that have proven true for centuries, and they include much more than the old sales funnel that has been the model that was used.
While all loops are by definition “marketing,” many businesses think in terms of separate departmental functions: Sales, service, and (promotional) marketing. This is thinking that comes from the old funnel paradigm. Marketing did advertising and promotions, the sales team did direct selling, and then the customer service group took over. The three functions never worried much about each other because the boss evaluated them all differently.