Hello Rutteger,
Regarding SiteSearch, this is from Google Support:
Exclude boilerplate content
"If your pages have regions containing boilerplate content that's not relevant to the main content of the page, you can identify it using the nocontent class attribute. When Google Custom Search sees this tag, we'll ignore any keywords it contains and won't take them into account when calculating ranking for your Custom Search engine... To use the nocontent class attribute, you'll need to tag the boilerplate content, and then modify your context file. This tells Google that you're using the nocontent class attribute."
Read the rest here:
http://support.google.com/customsearch/bin/answer.py?hl=en&answer=2631036
I think it is a great idea for you to have members use that field to showcase their collections in this way. It keeps the signature content relevant (at least at the forum level, if not for the thread) and increases internal linking.
Additionally, I would do the following:
- Limit signature privileges to members with a certain number of posts and/or other metrics (e.g. Kudos, points...)
- Do not allow external linking from forum signatures
I will leave this question open as a discussion in case anyone else has first-hand experience with traffic / ranking changes before and after removing signatures from a forum - or with handling the situation in some other way.
Lastly, Google is pretty good at recognizing boilerplate content. They have been dealing with forum signatures for years, and since the area is highly-prone to spam I would imagine they know what the signatures are on most major forum platforms. Thus, I wouldn't fret over it too much unless it is clearly causing you problems in the SERPs.
Good luck!
