Web sites: dynamic page extension versus paged navigation

Recently, more and more web sites are showing their content via dynamic page extension instead of paged navigation.

• Dynamic page extension: New content is appended to the current page. Examples:
• DZone and normal Twitter recognize when you are close to the end of the page and add new entries.
  
• Mobile Twitter has a link at the end of the page to “show more”.
• Paged navigation: New content is shown on a new page. Example: Google’s search results.

But good old-fashioned paged navigation has several advantages:

• Bookmarkable: You can return to where you currently are via a bookmark. Naturally, care has to be taken so that URLs are stable. For example, page numbers that count back from the current entry are not stable. Page number two will contain different entries as soon as the current entry changes.
• Finite amount of content: Keeping pages small saves resources. This matters especially on mobile browsers.
• Better scrolling: On one hand, there is less content to scroll. On the other hand, you can actually scroll to the end of the page, as a location.