Check out the post at TrivialTV blog that details, via a graph, the relationship between inbound links and visitors to a site (Great data and thanks for making it public)…
In August 2006 I painstakingly harvested data to investigate the relationship between # of links and vistors/day and the effect of syndicates. I’ve only shared the data with a few friends so far, but one of them has been hounding me to share the plot with a wider audience. With Matthew Hurst’s post about Readers Or Links over at Data Mining today, I decided it’s worth going off-topic for a day. So here’s the plot:
I only included sites that used sitemeter with public data access and that were registered with technorati. Nearly 1800 different sites are represented in the figure.
In aggregate terms, the graph is a good proof that inbound links drive traffic (of course some links are more valuable then other). But it still does not answer the questions about influence…Which of the sites, listed in the graph above, have more influence. Check out this interesting post on the ebiquity blog:
Matt Hurst has a great example illustrating why measuring influence as inlinks (what Technorati does) is too simple. Here are two blogs, their inlink rank as computed by Technorati, their average daily visits as computed by Sitemeter, and the trend in visits over the past year.
blog rank visits trend Michelle Malkin ~19 ~120K steady pink is the new blog ~117 ~200K increasing As Matt pointed out, measuring readership with tools like sitemeter is problematic. As I write this I realize that I read Matt’s post through his feed in Bloglines, so his blogs will not have registered a visit.
Of course, it all depends on what you mean by influence which is mostly a function of why you are interested in it. For example, if your goal is to sell shoes, ads in “Pink” probably have more impact. If you want to push your new book “Taxes are evil” then Malkin’s blog is the way to go. So influence also has to be measured with respect to the community you want to influence.
Other factors that can determine influence are the kind of visitors that are coming to the site (meaning are these influential visitors or not), what these visitors are doing once they are on the site and how engaged are they … Check out our previous post on the subject that deals with how the engagement level of the users can be gauged using the attention data. Another measure of the influence of blogs can be the number and quality of comments. Of course without a universal measure of the quality of comments, relying on just the number of comments, could be very misleading. Bloggers can just turn off the spam filter and that will generate a huge number of bad comments and thereby game the system for judging influence. But with a common gauge of comment quality, the number of comments can be a useful measure of influence. Developing and popularizing a universal gauge for the quality of comments, is a tough nut to crack but its importance cannot be overstated. I am looking forward to more research (I am waiting for the paper that ebiquity guys mentioned) and new ideas on how best to measure influence…Indeed the future of online communities might depend on it.
KarmaWeb 
I’m glad that you found the data interesting.
I think the whole topic of influence is pretty difficult since most people probably won’t agree on what makes a blog/site influential. Not having a clear definition makes it difficult to define clear metrics. Plus, a blog/site could be very influential in a niche and have absolutely no broad influence.
As for links driving visitors, it’s probably no surprise to you that there are generally two types of sites in the upper left corner of the plot:
1. sites with a majority of visitors from organic search (good SEO)
2. sites with a majority of visitors from referrals (good link placement on a few sites that have heavy traffic and good CTR)
Wow, Thanks for the hard work. While influence is very hard to gauge, your scatter plot shows a very clear, positive correlation between inbound links and inbound traffic. Many times we get so caught up in the idea of increasing our inbound links to influence our PageRank score, that we forget about the most basic and important reason for generating inbound links; driving traffic to our sites! I just wrote a long post on this very topic. I wish I would have found this post prior to publishing it. I will definitely have to add a link. Keep up the good work.