My own experience (across many sites) pretty closely supports what claarky is saying. Here's an example.
One of my ecommerce clients (the one I oversaw into a new platform last year) has soared with every Panda update. He's a brand, but he's not a big brand by a long shot. In fact his most direct competitor is the big brand in this niche, but only in catalog - we've been eating their lunch online for almost fifteen years.
This site does have a significant percentage of thin and shallow product pages (not a question of duplicate MFR content as much as a lot of specs and measurements.) But where that couldn't be helped, we built up the category pages, and added a lot of supporting CMS pages with text and videos and whitepapers to talk about applications and usage, maintenance, how to pick the right product, etc. In the cases where we have to go up against, for example, Amazon, for some products, we've built several related products into bundles and kits and all-in-one solutions that Amazon can't do. And we post *why* we've bundled products a certain way too, and we give the product line a branded name of some sort, and whip up a logo for it.
I don't pretend to know how Google does it, but I think Panda pays attention to this sort of thing. And I've been applying the same practices not only to other client sites but also to some of my own, and as far as I can tell, it works.
You don't have to be big, but you do have to look like you know what you're doing.