[ericclemmons]

As someone who has worked on the tech side of sites powered entirely by organic SEO, I've definitely seen the same penalties occur when cosmetically "cleaning up" URLs or code.

In the author's case, they moved to sub domain for easier maintenance. The article ended with a transparent way of keeping the old URLs and correctly improving the tech behind the scenes.

Be careful of changes, even if endorsed by Google, when things are working. More often than not, there'll be a mistake, you send the wrong signal to Google, and you take a hit. Only do it, IMO, when there's nowhere to go but up :)

[Scoundreller]

> More often than not, there'll be a mistake, you send the wrong signal to Google, and you take a hit.

There's probably a publication bias here. When people change things and traffic goes up, they don't run to tell the world about it.

Though anecdotally, I have a lot of reference-type content that has been bubbling up over the years seemingly solely because it hasn't changed at all in 7 years. The big players like to refresh their design and layout every few years.

[ericclemmons]

You're absolutely right!

In my experience, we've had more bad than good with URL changes.

The interesting part is that often a "URL cleanup" would result in a quick "boost" in traffic/rankings, but would continually slump, often even unrecoverable after reverting.

[paromi]

This is true. If it works dont change it. I had many experiences with google and penalties. Now im afraid even to add a banner to a site because google might not like it.