User Comments -- Pro & Contra

Fresh Content vs. Keyword Density

[Killah]

I was wondering if it's a good idea in the end to give our surfers the possibility to post a comment to our product pages. Every comment would be manually checked by a Moderator. However If you display 10 or 15 comments of surfers on your page about widgets, your keyword density for widgets will probably increased or decreased dramatically and frequently. People write what they think, not what the overall keyword density would like to see.
What are your thoughts about this, are comments from surfers a fresh-content-booster or an unpredictable factor that can hurt your rankings?

[tedster]

There is no hard line number used for keyword density these days -- ranking is no longer that simple or that restrictive. If you feel your users will benefit from comments, I'd say go right ahead.

[Killah]

And what do you think about the factors
fresh content from the (daily) comments
vs.
'aging' of the page (without new daily content) which gives stability in rankings

[tedster]

Similar answer -- there is no simple answer. Google accounts for different type of pages differently.

However, the longevity of the url, the address itself, seems to be the more important historical factor. If the article itself (the top of the page, IOW) is not edited but only new comments get added, I think you'll be fine. It's a very standard practice.