After reading quite a few of the forum posts for my last MSN/Live help blog I was struck by how passionate (or possibly obsessive) people were about ranking in the MSN/Live search engine.

As I do SEO every day, I am quite familiar with the relative traffic from the different search engines, and how much  traffic you will get for a number 1 position in Google versus a number 1 position in MSN/Live or Yahoo. In fact, back in September last year I blogged about how Neilson/NetRatings had determined the split of traffic in the UK.

At the time, I was more concerned about commenting on the fact that Google had a greater share of the traffic in the UK than in the US. However I became interested in the answer to the title of this blog when doing my previous researches on MSN search results.

Also, I have a couple of campaigns that for various reasons do not have a ranking in MSN/Live search, so they get zero organic traffic from that source. I have never worried overly about how much they were missing out on because I "knew" that it wasn't very much.

So, recently I decided I was going to quantify the actual amount: no more anecdotal evidence for me. According to the Neilson report I looked at before, it is 2.7% extra that they could boost website traffic with.

I took Google Analytics data for 14 campaigns at various stages of SEO for the last 10 weeks and compared the amount of traffic they got from MSN as a percentage of traffic from all search engines (so excluding direct and referral traffic). They are all based in the UK. Some use PPC and some don't, and some have better results than others.

Thus I have real data that gives a slightly higher percentage of MSN/Live search engine traffic than the Neilson report: 3.97%. So that's just less than 4% of traffic available.

There are a couple of inconsistent results in the list - one very high (three times more than average) and one is low (about half of the average). Some analysis of these sites results shows they are anomalous - one has only just gained Google rankings for key terms, and the other was not listed in MSN until part way through my measurement period. So, excluding those, the percentage changes, but not hugely, it becomes 3.54%.

The remaining sites are actually remarkably consistent in bringing in about 3-4% of visitors from search terms on MSN, regardless of where they are in the optimisation process or looking in detail at the positions for the individual search terms. So for me, this is a fairly definitive answer.

And as to how much energy you are prepared to spend on making sure your site is listed in MSN? I'd conclude that it depends how much business 3-4% extra traffic could bring to you. If you have 100,000 visitors a month, that's an extra 4000 people. If you only have 500 uniques a month, then it could potentially be a lot of work for an extra 20 visitors. You might be better off spending that same effort in increasing your position for one search term in Google to get a bigger effect. And if you are employing a search marketing firm, they should conclude the same.