The main difference is that a FEATURE does not pass the "SO WHAT" test,
A BENEFIT directly solves the problem of a NEED.
Buying benefits not features is something that can be used when buying any product but it is particular relevant when buying items like baby mattresses.. Also you want some criteria that your need will be satisfied.
Here is an example
You see a cot mattress advertised High grade nursery foam very good for your baby "That is a feature" offers nothing
Compare it to:-
This mattress has a weight of foam 50 /175 - average used in the nursery industry is 24/130- The first number "50" is the weight of the foam per kilo and indicates the density of the foam and this affects the durability.
The second number "175" is the amount of pressure in Newtons it takes to compress the foam to 40% of its size. This measurement is called Indentation Load Deflection (ILD) and this assess the firmness or the feel of foam and how it yields to weight and pressure and the support and recovery.
That is PROOF of a benefit
You can carry this to other functions your baby needs in a cot mattress such as breathability, hygiene, machine washable covers, temperature control, waterproof protection, environmentally friendly. etc.
BE WISE. Buy benefits that match your needs don't just just buy features backed with marketing blurb.