When I read about this issue…my first reaction was “what nonsense!”. I mean why would my PR suffer when I am giving some contextual links to my visitors, to read some references?
I found very contradictory opinions on this. Here are my learnings.
1. If you are providing only links, but no useful content of your own, then regardless of PR leak, you will certainly have visitor leak. This makes a lot of sense. If you don’t have anything to offer other than links, why should visitors visit that page? But again, if you have classified links, with some comments about every reference you are citing, that might be very useful to a reader, and your page might be worth bookmarking for him! an may be Google considers bookmarking as a factor.
2. If your site, as a whole has no outbound links, then crawler can’t proceed to some other interesting place from your site. This is not so good! This is called link sink. Flowing water to good to drink…once it’s still…it becomes undrinkable.
3. It is true that a link “donates” pagerank, rather than just “voting”…but still you are better of by giving out at least a few links to good quality sites. Google penalizes the sites that hoard pagerank like this.
4. If you give out some links, you can get back some links. Now, this is a very general rule. As with a normal social interaction, it might not result into reprocation. For example, frankly, I haven’t received any backlinks to this blog so far from the links that I put in my previous posts. Now, here is a contradiction…if you give out a link to an “authority” site, it might be good for you, but it’s unlikely that they’ll reciprocate and donate PR to you. So may be an ideal strategy would be to donate links to an “upcoming” site, than an “authority” one, who is more likely to have the manners and time to return the favor. Isn’t this eerily similar to real world social interaction?
5. Linking out helps in establishing context. My friend Saptarshi performed an experiment in which he proves that outbound links help Google to put the page in SERP for that particular context.
6. There are a lot of (over 100?) ranking factors in the ranking algorithm. Even though outbound links do reduce PR, they might have positive effect in some other parameters.
7. There might be different rule based on class of the site. Directories have huge number of outbound links, many of them not reciprocal.
8. You can use nofollow links to prevent leakage of PageRank.
The golden rule is always, as they say, content is king! If you have great content, and a decent site strcture, you will not need to worry too much about technicalities of PR.
I’ll keep posting more information as I find it…