How can linking remain a major part of a search algorithm when the majority of Internet users are unable to post a ‘followed’ link on the World Wide Web? For example Twitter, Facebook, wiki etc. are all ‘nofollow’. It seems only a very small percentage of links count. Ed, Caribbean

Following your interview with Eric Enge – you mention about “If Modified-Since.” We worked on many websites whereby the actual file timestamp doesn’t change but the content does as the pages are database-driven. How should we deal with such situations? Tommo, London, UK

On what basis you are increasing the PR for each PR update? Made, London

It seems that having relevant keywords in URLs is
very helpful. Does Google give higher importance to keywords in the path vs filename? E.g. http://example.com/tools/hammers/acme-metal-pounder or http://example.com/tools-hammers-acme-metal-pounder? Alex Black, Waterloo, Canada

When you search for something, lets say “LinkedIn,” you will notice there are some quick links on the search result such as “Jobs, About, Advanced” etc, how does that work? Assuming my website is #1 on the search results, how can I do that? Mohamed M, Ottawa, Canada

Any updates on “Site hierarchies display in search results” (AKA breadcrumbs)? My site has clear breadcrumbs, but Google isn’t using them in search results. Any tips for adjusting the links, URLs, or HTML code to get this to work? Nick, Chicago

More information about breadcrumbs: http://googleblog.blogspot.com/2009/11/new-site-hierarchies-display-in-search.html

Last year, one of my client’s webservers went down for over a day. Would this have affected the site’s PageRank at all? Hypothetically, what if this had happened for longer–could it actually drop the site from Google’s index? Land Lubber, Colorado

Can I use robots.txt to optimize Googlebot’s crawl? For example, can I disallow all but one section of a site (for a week) to ensure it is crawled, and then revert to a ‘normal’ robots.txt? Blind Five Year Old, SF, CA