@terentyev - sorry, can't edit my questions once submitted and I wait for approval (why?) the statement should read my question SHOULD be very specific, whereas my original question was much more general - you answered that question very nicely. Sorry for any misunderstanding

@terentyev thanks for the reply. We have no reason to believe these URL's are backlinked. These aren't consumer products that individual are interested in, our site is a wholesale B2B selling very narrow categories in bulk quantities typically for manufacturing. Therefore, almost zero chance for backlinks anywhere for something as specific as a particular size/material/package quantity of a product.

We have already initiated a canonicalization project started but we are stuck between two concerns from sales, 1) we can't wait for canonicalization (which is complex) we need sales now and 2) don't touch robots.txt because MAYBE the individual products are indexed.

So that is why my question is very specific - do we KNOW that Google will immediately de-index URL's blocked by robots.txt?

We have a very large store with 278,146 individual product pages. Since these are all various sizes and packaging quantities of less than 200 product categories my feeling is that Google would be better off making sure our category pages are indexed.

I would like to block all product pages via robots.txt until we are sure all category pages are indexed, then unblock them. Our product pages rarely change, no ratings or product reviews so there is little reason for a search engine to revisit a product page.

The sales team is afraid blocking a previously indexed product page will result in in it being removed from the Google index and would prefer to submit the categories by hand, 10 per day via requested crawling.

Which is the better practice?

What if the long, detailed content is for a page for which you cannot possibly win rankings for because huge, long-standing enterprises with high PA and DA already dominate the first few SERPs? Would it not be better to move the details of the content to the specific pages where they apply?

(Note, the site links are from a sandbox site and has very low DA or PA)

If you look at this page, you will see at the bottom a lengthy article detailing all of the properties of the product categories in the links above.

http://www.aspensecurityfasteners.com/Screws-s/432.htm

My question is, is there more SEO value in having the one long article in the general product category page, or in breaking up the content and moving the sub-topics as content to the more specific sub-category pages? e.g.

http://www.aspensecurityfasteners.com/Screws-Button-Head-Socket-s/1579.htm
http://www.aspensecurityfasteners.com/Screws-Cap-Screws-s/331.htm
http://www.aspensecurityfasteners.com/Screws-Captive-Panel-Scre-s/1559.htm