I recently set out to buy a new mp3 player and I noticed my process of research and purchase was very similar to how people buy homes.
I knew the features that I wanted in an mp3 player from day one, but as I researched some other devices, I added to my criteria some things that I didn't know existed before. I began by looking at the iPod nano, but soon discovered that while it stored 4gb of music, was easy to use, was recharable, and allowed me to create playlist, it didn't feature wireless synching to my computer nor FM radio, which some of the competition did have.
Well, in the end I opted for a Zune (by Microsoft), which for just a little more than the nano, has 8gb of storage, is smaller, has FM radio and wireless synching.
But the real eye opener was when I talked to a kid at Circuit City. He had an 80gb Zune and it was large and clunky but when I asked him why he bought that one over all the others, he's response was, "...well it's 80gb for the price of a 4gb." In other words, the most important thing to him when it came to mp3 players was size and the value of that 80gb Zune was too good to pass up.
Works the same way with homes, buyers seek out the best value (i.e. biggest home for the least amount of money) and sometimes that alone will superceed all other criteria.