There are many reason why individual store wants to store their wine.
The Economical Collector will buy young wines at low cost and with some ageing, they became more cost-effective for drinking.
The Everyday Drinker will accumulate a small collection of wines in their house so that they can be drank readily since some wines brand are not always available in the store.
The Serious collector will buy large amount of wines that suit his taste. This is to be cost effective and to be able to drink matured wines readily.