What constitutes "good" inventory?

Is "good" inventory a lot of things to sell? In a marketplace context, we often speak of one platform having better inventory than the other. Please correct me if I'm wrong, but this is often a statement that comes out of an inside-out view. Let me try and explain. 

My usual method to feel the elephant in the room, regular readers know by now, is to ask questions. So, when we say a platform has good inventory, do the customers also say that? Is buyer-feedback good enough on this topic or is non-buyer feedback equally if-not-more important? Let's take an example of shirts. If you have a million shirts and none in my size, do you have good inventory? If you have a million in my size but none that I like? What if you have a thousand that I like in my size and like the ones I like, and I'm not able to find them using your search and browse? What if I find what I need but I don't like the price or terms of delivery? Feel the elephant? Isn't it bigger than we imagined? The end of all these paths is no sale. 

But like they say, no two silences are the same since both could be the absence of a different word.

Let's get the basics out of the way. Having a lot of products to sell, on the shelves, is not a guarantee to a perception of good inventory. Second basic, the perception we just mentioned, is reality. There is no other sense of 'good' or 'bad' inventory. Third, all enablers we keep worrying about - having the right sellers or suppliers on-board, getting them to list everything they can - are all just that - enablers, and the customer doesn't think of those as inventory. 

Consumer in, the first thing to build would be Demand. If the consumer doesn't want it, or is not aware that the category exists on your platform, why even bother? The second could be findability. Through browse or search, the consumer must be able to find or discover the product. The third bit could be decision-tools if needed (spec-compare, shade-match, size-converter etc) along with the completeness of range (could mean SKU coverage for standard cataloged products and width otherwise). Then there is the catalog itself, or listing quality if the category is uncatalogued - often a stumbling block for marketplaces. And the picture still isn't complete without the all-important wrappers of price, payment and delivery terms. If all matches, and these don't, it is still, after all the effort, not a sale. 

Before we link a perception of bad inventory to bad sourcing, therefore, we should check for where the funnel is broken. It is possible for customers to, rightfully, feel you have bad inventory for more reasons than that.