Final answer:
Coca-Cola used product differentiation as its growth/expansion strategy for Vanilla Coke, conducting taste tests and creating a unique flavor and graphical look. This strategy helped Vanilla Coke become the best-selling Coca-Cola flavored variant of the decade.
Step-by-step explanation:
The growth/expansion strategy used by Coca-Cola in the case of Coca Cola Vanilla was product differentiation. Coca-Cola conducted taste tests and developed a unique flavor that offered consumers a new taste sensation while still maintaining the great taste of Coca-Cola. The company also created a distinctive graphical look for the Vanilla Coke brand, incorporating important aspects of the Coca-Cola brand while differentiating it as an alternative to regular Coke. This strategy proved successful, making Vanilla Coke the best-selling Coca-Cola flavored variant of the decade.