On 5/1/06, Erik Moeller eloquence@gmail.com wrote:
OR
- Due to mirrors, enabling or disabling nofollow has hardly any
visible effect on search engine rankings. In that case, it would be a placebo effect.
This hyphothesis would appear to be invalidated by our expirence removing spam from english Wikipedia. It is fairly common that a spam site will vanish off google right after removing it from enwiki, far too quickly for most of the mirrors to catch up.
For the few mirrors that we have a good enough relationship with to send a live OAI feed to, we can probably suggest that they nofollow externals coming in from Wikipedia. It's doubtful that they'd have a problem with doing this.
When it comes down to it though, most of the mirrors that have significant placement on the search engines are engaged in spamming SEO behavior themselves. If someone wants on one of those sites, there are probably even easier methods than inserting their content in wikipedia and waiting for it to be mirrored.
As I said, I think timing the addition of external links and enabling nofollow only for recent additions might be a reasonable compromise.
Only if someone can demonstrate some evidence that we are really good about removing bad links once they go in, and that anyone gives a darn if they get impact during the 24 hous their ill fated link survives. ...