Why Search Engine Traffic Sources Matter

By | September 18, 2009

By Kevin Lee, ClickZ, Sep 18, 2009

I’m a big fan of controlling traffic and knowing why you prefer one source of traffic over others. While advanced conversion attribution modeling can help refine traffic source preferences to an amazing degree, it’s also possible to gain insight by using a standard analytics package like the Google Analytics. Let’s looks at why traffic sources matter just as much as keywords do and why I’m hoping the evolution of the paid search landscape improves marketers’ and advertisers’ ability to control their campaigns’ paid search portions by traffic source instead of eroding it.

While a campaign management system that includes automated bidding logic is great for assuring that bids are set based on changes in conversion rate, lead quality, or average order profitability, sometimes you can use garden-variety analytics to create some ah-ha moments relating to the differences in traffic sources, even if the reasons behind those revelations aren’t immediately clear. Let’s dig into some fun stats about demographics and consumer behavior.

All clicks are not created equal. I’m not just talking about clicks from different keywords, either. I’m talking about clicks from different sources (engines), locations, ad formats, and ad types. A larger data set makes it easier to see the differences in one traffic source over the others. The following data are from D&B PowerProfiles, an online directory we work with whose very large diversity of content drives organic traffic, while a paid search campaign is used for a small set of specific keywords. Putting the data relating to conversion to leads aside and looking specifically at Google Analytics data is instructive.

Site stickiness can be a proxy for branding or engagement for a publisher. It’s a nice way to monitor whether visitors are getting deeper into your content. But what if there are significant differences in stickiness based on traffic source? For PowerProfiles, which receives hundreds of thousands of monthly visits from organic search (thus assuring a good data sample), Google organic traffic delivered 2.52 pages per visit last month. One would expect any engine, such as AOL, using a similar algorithm (or the same algorithm) to have a similar stickiness index. However, AOL visitors stayed on the site for an average of 3.53 pages per visit last month. Wonder why? So do I. Perhaps demographics explain some of the difference.

What does Quantcast say about Google and AOL visitors? Age, gender, and other demographic indicators are clearly different but probably don’t fully explain a 40 percent differential in site stickiness. Yahoo’s organic visitors are even stickier, with an average page view count of 5.48 pages per visit. This may be a combination of the different keyword and landing page types preferred by the Yahoo algorithm, or it may be a demographic factor. However, this number is now more than double the page view stickiness number from Google’s organic traffic. This knowledge can inform your paid campaign, at least out of the gate.

To illustrate the importance of keyword selection in the observed metrics, let’s look at the paid search traffic from Google. I selected keywords I thought would be very sticky and convert well for the site. Sure enough, the stickiness factor is high at 11.33 pages per visit: four and a half times the organic Google traffic stickiness factor.

Clearly, both keywords and the traffic source will impact your success, yet most marketers and agencies focus almost exclusively on the keywords.

We see similar data variations when looking at bounce rate, which is the percentage of people who leave the site after visiting only the landing page. Google organic’s bounce rate for PowerProfiles is 72.9 percent, while AOL’s is 51.8 percent and Yahoo’s is 35.8 percent. In the Google paid search campaign (which I really care about because each click is being paid for), the bounce rate is 14.3 percent. My team is looking for ways to make the organic pages stickier too, but a key point here is that one has more control over the paid search landing pages than over organic pages. Too much fussing with organic pages can kill the golden goose of good organic position.

One reason I felt compelled to reiterate the point that traffic from different search engines is different is that I want to be able to bid differently for traffic coming out of each search engine network. If I had the ability to do so within Google AdWords, for example, I would bid more for AOL clicks for many of my clients. If and when Yahoo and Bing traffic are accessible through one interface, I hope to be able to adjust bids separately.