Doorways are sites or pages created to rank for specific, similar search queries. They are bad for users because they can lead to multiple similar pages in user search results, where each result ends up taking the user to essentially the same destination. They can also lead users to intermediate pages that are not as useful as the final destination.
Here are some examples of doorways:
- Having multiple domain names or pages targeted at specific regions or cities that funnel users to one page
- Pages generated to funnel visitors into the actual usable or relevant portion of your site(s)
- Substantially similar pages that are closer to search results than a clearly defined, browseable hierarchy