We pay a fortune for lobster, it is a delicacy, but it is not long ago that lobster was poor peoples food. If you had nothing else to eat in New England in the 18th or 19th centuries, you would go to the beach and scrounge some lobster, and rules were in place to limit the amount of lobster masters could feed their indentured servants.
I remember as a kid that chicken was a delicacy, an occasional festive meal, Mum fed the Roberts tribe rabbit in a variety of ways as a cheap staple, bought from a bloke who went door to door down the street selling the previous nights haul.
How things have changed. Chicken is a commodity, flogged in supermarket specials, and rabbit is on the menus of the top end of town restaurants, attracting very high prices.
Marketing is all about managing the context and expectations a customer has of the value that can be delivered by your product offering. Preparing and consuming rabbit at home is now uncommon, but change the context to a restaurant, and suddenly the expectation changes, and rabbit is a sexy, modern dish that has attracted the chefs attention and skill, so is something very different to the skinned offering at the backdoor of my childhood.
Setting out to change expectations, often by changing the context as well, is at the core of the marketing challenge. Changing nothing, and competing on the existing commercial battlefield is just flogging stuff, and becomes a contest of price, not value.
Update: March 2015. This article from Entrepreneur magazine tells a similar story about lobster, and the way context and time changes perception, plus a very useful infographic.