Duplicate Content

If you experience a temporarily high crawl rate, it might be caused because of an increase in authority, or Google thinks the server can handle an increased load, or they might be finding a lot of duplicate content caused by things like URL parameters.

If someone copies content from your site, they might rank above you, for example when the original page is missing a good title tag and the copy provides more context.

Linking to sites with duplicate content won’t ‘usually’ result in a penalty.

Duplicating your content on other websites can result in those pages ranking equally or better if Google thinks it makes more sense.

URL Parameter settings in Search Console are a hint for Google, and they will validate them periodically. The Robots.txt disallow overrides the parameter removal, so it’s better to use the parameter tool to consolidate duplicate pages instead of disallow.

AJAX is not 100% equivalent to normal static HTML pages, but it should be possible to make pages rank as well. Avoid using fragments in URLs, and check with Fetch and Render.

Google will rewrite title tags which are keyword stuffed, or are duplicated across a lot of pages, and also to make them appropriate for the device.

If you have pages with duplicated snippets of content, such as product descriptions, Google will show the page which it thinks is the most relevant version.

If multiple sites are using the same affiliate/product content, Google will try to establish the original source, and allow a few other version to rank. They will be treated as separate sites which can rank independently for different queries. The suggestion is that this is fine provided you include some unique content. Later he also suggests this for pages with embedded videos.

Pages with content duplicated on other sites can still rank if they have something unique.