Google PageRank demystified: How To increase your page's PageRank, Part Three
April 15, 2007
This is part three of the Google PageRank demystified: How To increase your page's PageRank - Practical Tips series of articles. It continues from Google PageRank demystified, Part Two: Targeting incoming links, PageRank dilution by outgoing links, and Reciprocal links and their effect on PageRank.
Links pages and local PageRank
The links page is usually one of the pages referred to by the site's main navigation menu - and as such, gets a higher PageRank simply because all of a site's pages point to it. Even after logarithmic adjustment, this increase in PageRank is significant: for a site with 1000 pages, increase is 1.13, and for a site with 10000 pages, it's 2.23 (see the calculations on the preceding page).
Assuming a PageRank of 1.13 for the links page, if this page had no links other than to the 20-link navigation menu, the page's PageRank would be distributed back to 20 main pages - each receiving an increase in PageRank of 1.13 ÷ 20 = 0.06 from the links page.
However, the more outbound links the links page has, the more of its PageRank goes out, as well. If it links to 20 external sites, then half of its PageRank is contributed back to your site, and half is given away. If it links to 40 external sites, only one third is contributed back locally, or 0.02 per linked main page.
In other words, the more links of your links page point out, the more PageRank diverted away from your site.
Usually, at least. If most or all of these links reciprocate, and especially link back to your main page, then this increases the PageRank of your entire site. By a small amount, usually very small, but so is the PageRank you lose per outgoing link. And what inward-pointing links don't get you, is additional traffic.
- With reciprocal links, you trade link PageRank value to your main pages for an incoming link to your main page - a good exchange
- With reciprocal links, you gain traffic
- Great links - even if they lead your visitors to click away - make them happy. Happy visitors come back
- Even unidirectional outgoing links build your credibility
That said, lousy links will make site visitors think twice about looking to your site for advice. Don't include them, not even for a reciprocal link.
Finally, you have an option for the in-betweens: good sites, but not great, or of interest only to people with highly specific interests. Or maybe sites that you'd like to point your visitors to, but that won't link back, and you don't want to divert too much PageRank to. You provide multiple links pages. Only the top one gets a link from the main menu; the others are linked to from your main links page.
Thus, all these other pages get only one vote, from one page. They pass their (rather minimal) PageRank on to the links on those pages, including to your own pages - those on the main navigation menu. In other words, you can link to hundreds of outgoing links, organize your links pages logically and navigate them easily and professionally. And for every such page, some PageRank returns to your main pages - more than you would have if these pages did not exist! Highly recommended as a valid Search Engine Optimization (SEO) approach.
In practical terms, I'd suggest no more than 30 or 40 outbound links on your main menu page. If you have more outgoing links - great! - stick them on secondary links pages, again with no more than 30-40 links. Organize logically, make it easy to navigate. But link only to pages that are good or great, and get reciprocating links where you can.
The rel="nofollow" tag was developed to address so-called comment spam: user-submitted entries to blogs, on-line forums, guest-books, etc. that, rather than contain legitimate information, instead point to their web sites, both to boost their PageRank, and increase traffic to those sites.
When Google, Yahoo or MSN search engines encounter links flagged with this tag, they simply will disregard that link in calculating the target site's PageRank. So - no loss of PageRank to your own site, and no PageRank increase to those that abuse your decision to allow user-contributed material.
Instead of a link formatted like this:
Use a link formatted like this:
<a href="http://targetsite.com" rel="nofollow"></a>
Wikipedia and many others use this approach: yes, they have high PageRank, but they won't pass it on to some dØØd wishing to promote his own site ...
Use rel="nofollow" tags in visitor-submitted blog or forum posts; you don't want visitors to use your site to unscrupulously boost their own.
At the same time, don't use them in reciprocal links, unless they 'nofollow' you first. It's a good way to anger the other party, get a bad rep, and get unlinked from more than just their site. In other words, be fair.
Even in the absence of a reciprocal link, I typically won't use "nofollow" tags. If a site is worthy of my link in the first place, then they deserve my (typically very minimal) contribution in PageRank to their site. If you begrudge them that - certainly, you keep more of your PageRank locally by using "nofollow" tags all the time - others are also more likely to be stingy with you.
Finally, when I consider another site for potential link exchange, I view the page's source code. If they use "nofollow" tags in their HTML, then I'm not interested in a link exchange - it won't help my PageRank - unless I expect they'll bring me significant page traffic.
Modifications to Google's PageRank algorithms
Publishing its PageRank algorithms, and providing a PageRank display tool has logically led to people trying to manipulate their site's PageRank. Legitimately optimizing your site for appropriate indexing and ranking by search engines is appropriate - this is valid Search Engine Optimization. On the other hand, changing your code to clearly, artificially inflate your PageRank is taboo. Google and others have, of course, changed their algorithms took stay ahead of more abusive SEO techniques.
Consider the observations in this article a (very good) starting point to appropriate Search Engine Optimization, but not the final word. Some of the probable and possible changes to the PageRank algorithm as discussed:
- Every page, by the base algorithm, has at least a PR of 0.15 to share out. However, it may be that a page's starting PageRank is 0.15 ÷ N, where N is the number of pages in the Google index (over 9.5 billion pages, when I last checked). If true, this would give a page a starting PageRank of 0
- Pages without incoming links may actually be removed from the index
- Link farms (described on the previous page): search engines recognize these no-content-but-links sites and will either downgrade your site's value, or potentially even de-index your site
- Over-high keyword density, also known as keyword stuffing, and over-populating titles and headings with high-yield keywords, may trigger a search engine's SEO filter, leading to downgrading of a page's PageRank
- It is even likely that some, and possibly most or all, search engines now completely disregard the "keyword" META tag
- Link visibility and location on a page may affect its value
- A page's last-modification date may affect its rank
- XML sitemap files certainly can ensure that all a site's pages get crawled, and how often; the <priority> tag probably influences how relevant a search engine considers a page's content relative to other content on that site
So, what links do you pursue? How should you structure your site? What are appropriate, recommended, best-practice Search Engine Optimization techniques?
Note that the following recommendations are not exhaustive. Not one replaces the single most important factor in getting search engine traffic: content. High-quality, unique, content.
- Pick a threshold delta Δ PR value (i.e. minimum increase in your PageRank) for a potential referring page, as determined by the other page's PageRank divided by the number of links on that page; pursue only those that meet or beat your threshold, or
- Pursue a page if it's likely to increase your traffic significantly
- Realize that, no matter what the value of the incoming link, its effect on your page is almost certainly less than what you calculate
- Don't direct multiple links at routine content
- Concentrate your PageRank: focus your menu links to your main pages, only
- Direct incoming links to your site's main page, where you can
- Use only one URL for your main page, and even if you think you do, check it anyways, and
- Use only one URL per page, if at all possible. No variations
- Be judicious in what outgoing links you give away, i.e. link only to sites you think are relevant, and good or great, but
- Do give outgoing links where they're warranted. It enhances your site's value - worth much more than that small fraction of a page's value that you're giving away
- No outgoing links on your index page - it should be your highest-scoring page, and its links should spread its value among your next-most important pages: your own
- Links pages are expected; if appropriate to your site, build them
- If possible, place outbound links on a separate 'Links' page, and don't worry that its links won't add much back to your own site. For a site with many pages, this costs little (and usually gains you more)
- Place no more than 30 or 40 outbound links per links page; put extra links on secondary links pages, all logically organized
- Secondary links pages should only have one incoming link from your site
- Quality reciprocal links should be placed on your main links pages; lower-valued links on secondary pages - unless they truly belong on the main Links page
- Don't exchange links with low-quality or irrelevant content
- Don't seek reciprocal links from sites that use "nofollow" tags, unless you expect them to produce significant site traffic
- Don't use rel="nofollow" tags in reciprocal links, unless they do so to your first
- Don't use "nofollow" tags in your normal outgoing links - the small bit of PageRank you keep to your own site likely isn't worth the appearance of stinginess
- Do use rel="nofollow" tags in visitor-submitted blog or forum posts
- Use your head; your credibility is worth far more than a fraction of a point
- No keyword stuffing, and
- Create sitemaps - either in Google's sitemap.xml or ROR.xml format - and priority-tag the pages; then submit to Google and Yahoo
Again, help yourself to the Web Site PageRank Assessment Worksheet (for scoring prospective link pages, to see if they're worth pursuing), and drop a hyperlink to this page if you believe it's merited ... For Google's PageRank utility, download
and click on Settings, Options, More to find and activate the PageRank and Page Info button.
First page: Google PageRank demystified, Part One: Multiple-page sites, internal links, and the logarithmic down-ranking of PageRank
Second page: Google PageRank demystified, Part Two: Targeting incoming links, PageRank dilution by outgoing links, and Reciprocal links and their effect on PageRank