I spent several hours on Saturday reworking the navigational structure of ad pages on the various community sites. Several of these pages had over a hundred links. I also reworked the prev and next buttons so that point directly to the previous and next page, rather than using a redirect.
The main reason for doing this was that Google's warns people not to have more than 100 links off a given page. Also, I noticed several search engines were indexing the redirect code...rather than the real page.
It is strange, but search engines tend to do a better job indexing navigational structures than pure content (not that any of the pages in the ad section really have content). In some ways, that really is not bad. The point of a navigational structure in a web site is to get people to the content they desire. Getting a person into a good navigational structure is a good 50% of the battle.
It will be interesting to see how these navigational changes affect traffic through the community sites.
BTW, the sad truth is that I have no way to make money off the local traffic in a community. So I have a careful balance that I must strike between directing people to national web services so I can pay of the site and local resources.