As a link builder, one of the many things you can use to assess the level of competition in an industry is to check the backlinks of a few of the top competitors. Unfortunately we don’t get too much help from the search engines here, as they all report wildly different numbers and it’s impossible to tell which links count in the eyes of Google. I believe that the 80/20% rule applies to link building, where 80% of the link pop for a page or site is obtained from 20% of the links. I actually think it’s closer to 90/10, but as with most things in SEO, it’s unprovable and not information you’ll find in a backlink analysis.
Using Search Engine Land as an example, you can see the inconsistency between reporting:
Yahoo Site Explorer: 573,000
linkdomain command: 325,000
Google link command: 6,800
MSN link command: 0 (they blocked it again)
Alexa: 143
Two things to note here:
1) It’s common knowledge that Google’s backlinks are only a sliver of what is really being counted.
2) Alexa reports unique domains that they have data for linking to a site, not total links
What to do with the data
Regardless of the numbers reported by the engines, it’s not worth it to go over these with a fine tooth comb. I would recommend using Joost De Valk’s SEO link analysis firefox extension and trying to get a good idea of the different types of links that your competitors are getting. The extension will list the PageRank, anchor text, and whether or not it’s nofollowed. What I generally look for are types of links the competitors are getting. In order to do this I think the “linkdomain:site.com -site.com” works best as it provides you the most flexibility to filter the data.
For example, using retail giant Walmart as an example, to find how many directories a site may be listed in, I use a search in Yahoo like linkdomain:walmart.com intitle:directory. This shows all the pages that have the word ‘directory’ in the title that link to walmart.com. There is margin for error as some directories don’t have the word ‘directory’ in the title and some of the pages that do have it may not be directories, but I’ve found it to be reliable enough to give a quality snapshot.
You can also do the same thing to see how many links they have from blogs by doing a query like “linkdomain:walmart.com blog.” This shows you how many links they have from pages with the word “blog” in it. You could filter it a step further and search for only .edu blogs using a the query like “linkdomain:walmart.com blog site:.edu.”Again, the same margin for error exists for the reasons mentioned in the above paragraph, but for sites that don’t have blogs in Technorati (authority score in Technorati = links in the past 6 months) this is another reliable snapshot.
You can slice it and dice it any way you want which is why I really like utilizing Yahoo explorer more than any other tool. Depending on what you’re looking for, there are an infinite number of ways you can use this to help you in your quest to build links.