I'm doing some work on a foxycart e-commerce site selling automotive headlight bulbs amongst other things.
I've noticed that a lot of the site's competitors are dealing with variations in fittings by listing the product in each size. For example in terms of headlights, they list Product A Size 1, Product A Size 2, Product A Size 3 etc..
Surely this is bad practice, especially as the content is duplicated. Shouldn't google be punishing them?
The reason I'm asking is that the site I'm working on lists the products as normal and then uses a drop down box for the customer to select the size they require.
I imagine the answer depends on the specific market in question. Shoes, for example -- it would be ridiculous for a shoe-selling website to have a different page for each different size of the same model/color, right? It'd be impossible to navigate.
But the headlights industry might have some fundamental differences that require a different page for different sizes of headlights. 2 criteria to consider:
Does each product include a large amount of sizes, like shoes, or few sizes, like under 5? The fewer sizes, the more feasible it is to have a separate page for each.
Are the customers going to be searching by size? (seems likely with this particular type of product) If so, it may be beneficial to have a separate page for each, but there may be other, more sightly solutions.
Think experience, after all traffic does nothing for you if it doesn't convert.
Let's say sell shoes and logically each visitor wears just one size. As a shopper I'll end up on page with one size, say a 10 in mens. But I don't wear a 10 so what's more likely... that I'll search around your site looking for my size or that I'll click back and go to the next site? Unless your price is amazing there's no reason to keep going when I can go elsewhere with less fuss.
Now if your store has a limitation where you can't search on sizes unless they are different products that's something worth thinking about more and ideally building a module to address. REI does a great job of this sort of filtering for example...
As for content. Sure you're going to have a near duplicate but I suspect you can get around that with a little structured data on the products [telling the engines each is different] and just having them ignore all the sub-versions entirely.