Blog Post

Differences between Adwords, adCenter and Yahoo Conversion Tracking


We've been working on expanding our PPC dashboard to include Yahoo and adCenter data. This is an important part of our PPC Management services. While all three engines have adopted a similar structural hierarchy there are enough nuances to make presenting a consolidated view of the data pretty difficult. This post explains our findings in how each engine attributes conversion events to the initiating clicks and media spend.

Search Engine Conversion Tracking vs Google Analytics

First, let's investigate why we would want to use Google, Yahoo and Microsoft conversion tracking instead of just using Google Analytics.

Each method for measuring conversions has a different way of selecting the source to attribute a conversion to. It is a little bit like selecting tax lots when selling a stock. FIFO or LIFO. You can attribute the conversion to the original source and keyword or to the final source and keyword. Google Analytics always attributes conversions to the most recent source of visit to the site. So, if someone clicks on a PPC ad, bookmarks the site and then returns and purchases, Google Analytics attributes the conversion to the bookmark visit. The downside of this approach is that you'd really want to credit that PPC visit since that is how the customer initially found the site. There are some ways to try to overcome this with the Google Analytics nooverride tag

The conversion tracking tags on Adwords, adCenter and Yahoo all attribute the conversion back to the last click. That is a pretty good approach. The one situation this doesn't cover is when a person clicks on a category search ad (e.g., plumber) and then searches again for the plumber (e.g., joe's plumbing) and takes an action on the second click. In this case, Joe might think he is getting more brand search conversions than he really is but at least is tracking them back to the appropriate search engine.

Matching Conversion to Click

We import a daily feed of Google data and display it on our reporting dashboard. We realized that in some cases our count of conversions didn't match the Adwords data. Impressions and clicks matched but not conversions. We did some digging and determined that Google attributes conversions back to the day that the click occurred. If a click happens on Day 1 and the conversion happens on Day 3, Google Adwords will show the conversion on the report for Day 1 even though it happened 2 days later. That explains why our conversion counts weren't working. We were grabbing the report and not going back in time to update any late conversions. According to Google, they update conversion counts for up to 30 days after the date of the click.

When looking into adCenter, we determined that Microsoft attributes the conversion to the date of conversion. In the example above, the Day 1 click with the Day 3 conversion gets attributed to Day 3. Here is an FAQ on adCenter that covers this.

We are still looking into Yahoo's approach. I'll update this post when I figure it out.