I have a website that has articles that are #1 for targeted keyphrases. I'd like to allow users to add their comments to the articles - but, I do not want to do it in a way that might affect the #1 search engine rankings I've worked so hard to achieve. My concern is that the additional text will dilute the keyword frequency. Can anyone tell me a safe, solid way to add comments to high ranking pages in such a way that my search engine positions won't be adversely affected?
I think if you already have good rankings for that page, you probably shouldn't bother with comments. I doubt any comments would bring down your ranking, but you would still have to deal with the comment moderation including unavoidable spam. You mostly achieved those rankings based on your backlinks, not on your keyword density. If you do want to try adding comments to spark user interaction, your safest bet is to use nofollow comments. You should also have a good spam filter in place.
I already would plan on using nofollow, having a captcha system, and a strong anti-spam system (including comment moderation). Yes, I want to add comments to spark user interaction. The question is, can comments adversely affect SEO and if so, how do I prevent that? Worst case, I can position the comment section as an empty DIV as: <DIV Class="CommentBlock"></DIV> and then write the contents of the comments to the class with innerHTHL with an included JavaScript. But I don't know if that is completely necessary (and I don't like the client browser overhead it would cause). Or, I can wrap it with an iFrame, but I don't know the pros or cons of doing that. I'd like to hear from someone with solid SEO experience with this issue.