I ask this question based off 2 main areas of reason. The first falls under duplicate content and the second falls under value.
I have 100s of pages on a site that are pretty much checklists. They contain a title, description, image and some other minor meta data. If you click the items title it will bring you to a page that lets you leave comments about this item. Currently i only have the main checklist page added to my sitemap. I would of course like the items to also get indexed, but since all the data except comments is on the main list, is this duplicate content?
For another example I also have around 500,000 records for user statistics. The user can enter a username and see a little bio and a nice amount of information about the users stats such as amount of items checked, time spent on the site, products owned (nothing sensitive or private). The pages are viewed quite a lot through links on the site, so i would consider them of value. My issue here is that the site itself has about 2000 posts and around 8000 lists. Adding 500k pages like this will far outweigh the others. Will this negatively affect the site in any way if i were to add these to the sitemap?
Is there any sort of guideline to determine whether a page is worthy of the sitemap or not?