Analytics How-To: Measure Duplicate Links on a Page

A page that links to another often does so from several different links on the same page. The most common example is a home page with a navigation bar at the top and another with text only links at the bottom. Since both links point to the same URL, the request appears identical regardless of whether the user clicks the top link or the bottom.

Marketers sometimes need to know which link is really being used more, since this can heavily influence site design decisions.

A web analytics tool is able to distinguish these links if a parameter is added to them within the HTML. Each time the link is used on a given page, a parameter with a different value should be added so the links can be distinguished when the tool reads the logfile.

Since this requires a modification to your site, you should plan carefully and thoroughly understand what needs to be done. The following list may be used as a guideline for planning parameter tagging:

1. Decide on a single parameter that will be used to distinguish and that has an easy to recognize name such as 'from.'
2. Decide on a consistent set of values. For example 'from=topnav' and 'from=bottomnav' or 'linkid=1' and 'linkid=2.' The value needs to be unique within a page for a given link, but does not have to be unique for every single link and page. For example the two links 'news.php?from=topnav' and 'product.php?from=topnav' have the same distinguishing parameter, but this is OK because they're referencing different pages.
3. The parameter must appear as the last one on each link. For example: news.php?catalogid=5&from=topnav.
4. Once the site is modified to include the parameter on each page, you'll need to set the date range in your web analytics tool to include only the dates after this.
5. Be aware of possible side effects in search engine optimization.

Adding this parameter to each link could affect the ability of search engine spiders to crawl and index your site. This depends on the particular search engine, and the technology it currently employs. You may want to consult a search engine consultant and have them evaluate this for you.