I discovered a very interesting thing happens when you change the permalink structure of an existing WordPress blog. It actually makes perfect sense but is something I did not think of ahead of time. This post just alerts anyone considering a change so you are aware of one possible adverse consequence. WordPress permalinks can have quite an impact on your site’s search engine rankings. It quickly gets quite complicated explaining why and is beyond the scope of this post, but if you want a good historical summary of the subject, I recommend this post on permalinks at Otto on WordPress. You can also read the recent post I wrote on the WordPress numbering system.
Changing the permalink structure on an existing WordPress site used to require editing your htaccess file or using a permalink redirection plugin. The latest versions of WordPress do seem to handle permalink changes with no trouble so you can get away without a plugin or code changes. Recently I changed mine on this site to make the url that appears in a reader’s browser window more sensible. If you look above you will see my permalink structure no longer contains the category, or the post id number. It just is the site url followed by the post or page title. Simple and concise, but a problem was created with this change that I guess really has no solution.
Some of the posts here have been shared on Digg, StumbleUpon, Facebook, etc. many times. I have one post that has well over 100 Diggs. The thing is that all the posts that were shared before I changed the permalink structure were shared using a different url than they currently display. The shares are still on the services like Digg and StumbleUpon, they just have the old url. When people click over from those sites, they are seamlessly routed to the correct post at the current url so all seems well.
What happens on the post itself however is that the shared number is displayed incorrectly. As an example, say someone came across one of my post on Digg that showed it had been shared 120 times. When they click through to read the post, the Digg button on the post will only show shares since I changed the permalinks. So a post that showed 120 diggs on the Digg site, may only show 3 or 4 diggs here at this site. Not too big a deal, but for those of us that treasured the big numbers of shares some posts have, it is a bit of an ego deflater! Maybe that is not so bad a thing, but I still wish there was a way to update all the links on the sharing services to reflect my new permalink structure.