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I think you'd want to keep your category pages in the index as these are the brand names that people are going to be searching for. As for the the actual articles themselves - first I notice that you have articles going back to 2009. As these are date specific coupons they're not really of any value any more. I think if it was me I'd cull these and set up redirect to point any links back to the the home page.(I'd be interested to see what other think) With so many pages, (4000+ in 2009, 6000+ in 2010) I don't think you're going to be able to easily point the articles URLs back to category pages. As for the individual articles/offers themselves. How do these perform at the moment? How much search traffic do the individual articles get. What about the category pages? What about inbound links? What are people linking to/sharing?

Yes remove any link pointing to it, if you do that it will eventually fall from the index, but will take some time. If you have an external link pointing to it then it will not go away while that link exists, but in those circumstances you need to and want to 301 it to a relative page