How Google Detects Doorway Pages: Inside Their Algorithms and Techniques

https://www.4shared.com/office/VvFz6kYdjq/pdf-41786-5281.html

Doorway pages are the SEO equivalent of a tourist trap with a fake ticket booth. It looks legitimate from a distance, but the intent is to funnel traffic somewhere else, usually to inflate rankings, harvest clicks, or route users into a page farm