Changing the URLs of pages containing narrative content like articles has several disadvantages, especially for a content site:
- Readers’ bookmarks to the site’s pages break
- Links archived in electronic mediums (e.g. emails, documents) & print mediums (e.g. books, magazines, newspapers) to evergreen content1 like articles or news stories break
- Incoming links from other sites break
- Search engines drop the ranking of the pages
- It becomes harder for readers of the site to find content
- The site loses credibility with the readers
- The points above result in a significant loss of traffic to the pages, which in turn results in a loss of revenue
The idea of permanent links to content is gaining renewed popularity with blogs. Almost every blog entry has ‘permanent link to this item’ link.
Years ago, when I decided to move my web site from an html+cgi platform to a better dynamic web site platform, I selected Microsoft’s Active Server Pages (.asp). I was disappointed that all my content page URLs were going to have to change from the .html extension to .asp, but I reasoned it would be a one-time change. Going with Microsoft’s new standard seemed a safe bet, so I did 
A few years later, when the .NET platform came along, I was even more disappointed to learn that I’d have to change my content page URL extensions to .aspx. I figured that with the criticism MS has received with the change from .asp to .aspx, MS would settle on .aspx for good. So this time, going with the new MS standard was surely a safe bet, so I again began to slowly change my pages extensions again
Now MS came up with yet another extension for file names in URLs, .mspx which is beginning to show up on some content pages at microsoft.com. Perhaps it is a sign to switch to a web application platform with stable URLs filename extensions like PHP or JSP. (The PHP developers listened to the user community when they tried to introduce the new .php3 filename extension and remained with .php.)
Yes, there are ways to preserve URL filename extensions while changing the underlying technology, but none of them is a good solution:
- URL Rewriting. There are some URL rewriting engines on the IIS platform, but none is well-supported, strongly established in the market, or feature-rich like mod_rewrite on the Apache platform
- Redirects. The way to do this correctly is via server configuration. On IIS sites at hosting providers, that is often not an option.
- Mapping the old extension to the new technology. Since .asp, .aspx and .mspx pages are incompatible, it is impossible to slowly migrate the pages, a few at a time. This also results in an unsupported usage of the platform. Most hosting providers will not do this
- Staying with a deprecated technology (keeping my pages .asp) is not an option either since that technology platform is on its way out and new features are not being added to it. Also, as a technologist, I don’t want my site’s pages to display an obsolete technology
The fact that microsoft.com’s own pages have been changing extensions from .asp to .aspx to .mspx is a sign that the way they have designed these technologies to not be backward compatible, sites will have to change their pages extensions.
Ideally, content publisher and readers should not have to deal with these issues. Perhaps I should use a URL rewriter and completely do away with url filename extensions on my site. Then I could have some pages as .asp, some as .aspx, some as .php and show readers only a uniform .htm extension (or no extension at all). Maybe I will move to PHP and do this as Michael Radwin at Yahoo suggests in his blog.
- evergreen content: pages expected to serve their purpose for a long time. [↩]
