Does the height of the pile matter in choosing a carpet?

Tall fibre in carpets does not necessarily translate to a harder or better wearing carpet.

The higher the fibre the better propensity it has to fall over when you walk on it and flatten in a shorter period of time. When a human being walks on something, all their weight is concentrated into a small area. It is even more so on stairs. An average-sized woman wearing high heels exerts approximately 1100 pounds of force in their heels.

Thick does not always mean good. Some of the best wearing products that you can get are short and very tightly packed together. You want a lot of fibre per sq. Inch, therefore the heavier the weight of a carpet the better. The reason for this is because the fibres support each other, this makes tightly packed carpet wear very well.

Softer and thicker carpet is nicer for a bedroom.

Low and dense carpet is a better choice for stairs. The weight or concentration of fibre (tufts per square inch) is more important any areas with very heavy usage and in hallways and on stairs.  

So in choosing your carpet quality be aware of which carpet works best in which areas in your home and always bear in mind that the look, feel and durability is appropriate for use in your home, office, place of worship or the space in which the carpet is going to be fitted.