Economies of scope captures the idea of having efficiency in variety. I've come across this idea only in producer theory to capture the idea that companies may benefit from their ability to reduce cost of production through horizontal or vertical integration.
Quoting Micheal Carter from his book Foundations of Mathematical Economics,
The production technology displays economies of joint production or economies of scope at y y1; y2; . . . ; ym if the total cost of producing all the outputs separately is greater than the cost of producing the outputs jointly
Is there a consumer theory equivalent of the idea of economies of scope?