PageRank is something that many within the search engine marketing and optimization industry are familiar with. PageRank reflects Google’s view of the importance of web pages. Pages perceived as important receive a higher PageRank and are more likely to appear toward the top of the search results.
Years ago, the “nofollow” attribute was introduced, which enabled webmasters the ability to tell search engines to not follow a specific link from a page. This attribute essentially tells Google and other search engine spiders to ignore the link and not transfer any PageRank to the page it links to. This can even be used internally on websites to tell the search engines to not transfer PageRank to interior pages. This led to what is known as “PageRank sculpting” where webmasters started to manipulate how credit flows throughout their site. With PageRank sculpting, webmasters could prevent losing valuable credit on links to unimportant pages and the credit that would have been given to those pages could be redistributed, providing the other links to more important page (those without the nofollow attribute) with more credit. PageRank sculpting is done in theory to achieve higher rankings for internal pages of a website by not wasting credit on less important pages.
However in 2009, Google stated that using nofollow attributes will no longer allow you to redistribute credit. Instead, if you use the nofollow attribute, let’s say on 5 links on your homepage, the credit for those 5 links will disappear. The credit that those 5 links would have received without the nofollow attribute will no longer be distributed to other links on this page.
Since this is the case, it forces webmasters to think about the number and value of links they have on any given page. If you have too many links on a page, and some of them are nofollowed, you’re essentially throwing away credit. For search engines and users, you should ensure that the links you have, particularly on your homepage, are to valuable interior pages. There may be times when you do want to include the nofollow attribute, such as for log-in pages, shopping cart pages, etc. After all, there is no value in having these pages rank in the search results.
Here is a link to a post on Matt Cutt’s perspective on the nofollow attribute and PageRank sculpting. In general, it’s recommended to let PageRank flow throughout the site. Focus on creating a site worthy of garnering quality links, and an architecture that is friendly for search engines and users.
Sometimes you may have certain pages on your website that you do not want indexed by search engines. Just recently, we developed an online order form for a client that should not show up in search engines. To ensure that a page does not get indexed or crawled by search engines, it is important to do 3 things:
1. Add a rule in your website’s robots.txt file. Assuming the page you don’t want indexed is order.htm:
2. Add a “noindex, nofollow” robots meta tag in the head section of the page that you don’t want indexed or crawled:
3. For each link leading to the page that you don’t want indexed or crawled add the following “rel” attribute to the anchor tag with a value of “nofollow”:
That’s pretty much it. It should be noted, that until recently, it was thought that you only had to add the rule to your robots.txt file to prevent pages from being indexed and crawled. However, Matt Cutts from Google gave some insight stating otherwise in a video posted on his blog (http://www.mattcutts.com/blog/robots-txt-remove-url/).