I read the interview with Matt Cutts today and it talks about the different uses of noindex, nogollow, and robots.txt. He states (1) whether they stop the passing of “link juice” (PageRank), (2) whether or not the page it still crawled, and (3) whether or not it keeps the page out of Google’s index.  

From what I understood…..The nofollow (link attribute) is used so Google won’t follow a specified link, no link juice flows from that link, although the page the link is on will still be crawled and indexed. The interview makes some interesting points, although a point that really sparked my interest was when Matt Cutts states...

“Matt Cutts: That’s right. Another good example is, maybe you have a login page, and everybody ends up linking to that login page. That provides very little content value, so you could noindex that page, but then the outgoing links would still have PageRank.

Now, if you want to you can also add a nofollow metatag, and that will say don’t show this page at all in Google’s Index, and don’t follow any outgoing links, and no PageRank flows from that page. We really think of these things as trying to provide as many opportunities as possible to sculpt where you want your PageRank to flow, or where you want Googlebot to spend more time and attention.”

Eric Enge: What we've been doing is working with clients and telling them to take pages like their about us page, and their contact us page, and link to them from the Homepage with a nofollow attribute, and then link to them using nofollow from every other page. It's just a way of lowering the amount of link juice they get. These types of pages are usually the highest PageRank pages on the site, and they are not doing anything for you in terms of search traffic.

So, we can control where and how much “link juice” we want to flow throughout a site via the nofollow link attribute. Why would he speak of sculpting where we want PageRank to flow unless each page only has a “limited” amount of PageRank to distribute? This has me thinking that a page holds a certain amount of “link juice” and can only distribute a certain amount to each page it links to (whether is evenly distributed or not, I don’t know).

I would like to get the SEOmoz community's thoughts on this as I have not read much about this. Should I start being stingy with my link juice and only quench the thirst of those pages that deserve it most?