Imagine you're a consultant tasked with revitalizing a local coffee shop known primarily for its coffee and pastries. Using the concept of product decision, consider this question:

Product Portfolio: Should the coffee shop expand its product line beyond coffee and pastries? If so$,$ how could it leverage its existing brand and customer base to introduce new offerings $($e$.$g$.,$ salads, sandwiches$)?$ Should it consider developing additional product lines $($e$.$g$.,$ merchandise, subscription boxes$)?$ Discuss the potential benefits and challenges of each approach.