I'm working on a website that has a bunch of orphan pages with pagination. For example, one product category will have an orphan page, and since there are hundreds of products in that category, there will be pagination. Interestingly, pages 2 onward of the paginated content are indexed by Google, whereas the original orphan page isn't. There don't appear to be any external backlinks to the paginated content either. Is it possible that the orphan, non-indexed page is getting the subsequent paginated content indexed? It doesn't make sense to me, but I just wanted to find out if anyone else had experienced this phenomenon.
Could be due to a lot of things. First up, they don't index every page, even if you provide a sitemap. Then it may have something to do with history. For example at one time I was wondering how certain pages could appear in Google search results when I hadn't submitted that new site yet. The answer to that enigma was that when I spelled out the links over the phone, the client typed the URL into the Google search box instead of the Address box. Apparently this is something that total newbs do. So Google then spidered those pages and retained them in their database.
So if ever you want to keep a new release secret until the launch, don't let newbs know about it.
Getting back on track... this may be related because someone or two may have typed in links to pages 2 onwards in the Google search bar instead of the address bar, thus elevating the importance of pages that would otherwise have been omitted from spidering.