Different referral sources bring different volume/value traffic

I've found quite a big variance on the quality (and quantity) of visitors generated by different referral sources. The differences in behaviour of these visitors is significant and demonstrates that quantity isn't the same thing as quality. It also shows you can spend a lot of time bringing in visitors who aren't really that interested in what you have to offer.

Quantity

Below I've included some recent figures towards the end of 2008 for our site.

You can see from this visitor information out of Google Analytics:
- Organic Search: 43%
- Pay Per Click Google Advertising: 30%
- Direct: 9%
- Yellow Pages: 2%

In short about 75% of traffic is generated from Google (if you include Adwords advertising which does span other sites as I've turned on contextual advertising). The other 25% is sourced from 50+ other sites including specific medical directories, the hospital where they work and their online Yellow Pages ad.

Interestingly this has changed a fair bit since August 2008:higher % of organic search as we add more content and creep up the SERPs, less direct traffic (less paranoia about the site still being available) and some new sources of referring traffic eg Yellow Pages.

Quality

Looking at the quality of the traffic brought by these methods eg bounce rate, time on site or, as I have shown below, pages/visit - you can see some interesting trends.

Compared to the average visitor (let's call them someone searching on Yahoo):
On the negative

people visiting from the article sites visit 70% less pages (and they have a much higher bounce rate so this is our least successful referral source)
organic Google searchers visited ~20% less pages (perhaps they got what they wanted and left).

On the positive

Adwords searchers visited ~20% more pages (so it would be fair to say by requiring people to click on an ad is some form of qualification of the prospect)
people referred from the health directory visit ~30% more pages
people referred from the hospital or the Yellow Pages visit ~80% more pages

Summary

So if we make the assumption that the Pages/Visits metric (or the bounce rate or the time on site) is a fair measure of the quality or value of these visitors then we see that in general a visitor from a referral source that is relevant to your industry or is a relevant business directory is worth more than a regular search visitor. (In our case the business directory is relevant to our local area as is the hospital so these are highly relevant visitors as opposed to Google searchers who may be over the other side of the world).

Are the 1,100 Google organic searchers worth more than the 170 visitors from the hospital and Yellow Pages? I couldn't tell you definitively on the data I have but they would need to convert 8 times more readily to bring in the same number of customers. The quality information above would seem to indicate that is the case but then of course there is the little issue of cost...

P.S. Anyone have any idea why the images through Blogger seem to be so lousy? Maybe it is the way I'm saving them.