It is a Google’s world, and as webmasters we live and die by our search rankings, right? One of the factors that both influences search rankings and that most people seem to care about is the Google PageRank. More specifically, we want as much PageRank as possible!
Now aiming to increase the PageRank of your pages is fine, the problem is when misconceptions around the PageRank algorithm affect the way webmasters behave.
One of these misconceptions is to assume that when you link to external websites you will be losing PageRank from the page where the link is placed. I call this the “bucket view” of the PageRank algorithm.
That is, people mentally compare web pages to buckets, and backlinks to streams of water. The more streams of water you have, the more water your bucket will have, and thus the higher your PageRank. However, under this analogy external links on your page represent little holes in your bucket, so every external link will leak some water and end up reducing your PageRank. Put 100 external links on your page and all the water will be gone!
This analogy is somewhat logical, but it is NOT how the Google PageRank algorithm works.
The PageRank of a page is only affected by the number and quality of its incoming links, and not by the outgoing ones (you understand this by taking a look at the equation used, but I won’t get into that because it is beyond our purpose here). Obviously if you link to 1,000 sites or to bad neighbors from your page it might get flagged as spammy and be de-indexed, but that has nothing to do with its PageRank, which would remain intact.
If you have an internal page with a PageRank of 5 (keep in mind the real PageRank values are not integers but rather floating points), placing 10 external links on that page would in no way affect its PageRank. The only thing that would happen is that each of those linked pages would receive a link juice of 0.5 (the value of each link is equal to the PageRank of the page where they come from divided by the total number of outgoing links on that page).
Now the reality is a bit more complex and we would need to take into consideration other details to make a complete analysis. For example, you will still lose some PageRank if you link to external websites because if you had not linked there the link equity of that page would flow back to your homepage and be distributed equally across your website. This is the so called PageRank leak, but it is not as significant as most people believe.
Despite these nuances, therefore, the moral of the story remains: linking out is not supposed to directly reduce the PageRank on your pages. In fact there are plenty of pages that contain dozens of links and yet rank in the first positions of Google’s result pages for competitive keywords.
If you ever refrained from linking to an external site because you feared you would lose PageRank (I have been there too), forget that. Linking away to relevant and valuable pages is good for everyone.