One may not think of this topic much because it may seem trivial on the surface, but the mattress industry is highly dynamic, with changes happening all the time as well as new innovations coming onto the scene.
Case in point, in recent years a type of material has become very fashionable in terms of it's function- latex mattresses. It seems like if you were to interview the leaders of the mattress industry, they would tend to nod their heads and agree that this is where the future is headed.
With latex material mattresses, there aren't any movable parts and therefore it wont' break as easily. Latex mattresses also tend to last as far as it's contours and shape is concerned relative to other types of mattresses.
Usually latex mattresses have warranties that cover it from breaking down in any significant way. For example if latex mattress goes down by about an three quarters of an inch, many stores will actually replace your latex mattress. For other mattresses such as coil based ones, the warranty will cover mattresses that go down by an inch to an inch and a half in some cases.
That is a basic introduction to latex based mattresses, feel free to discover the difference for yourselves.