The cost of acquiring new leads and customers is growing. And the pace of ad-cost inflation is only likely to accelerate with the departure of our beloved third-party cookies. As a digital marketing leader, how can you navigate higher costs while still hitting your acquisition numbers?

One customer experience (CX) metric that can help is the well-established but rarely used Content Interest Index (CII). It focuses on CX demand instead of ad-driven supply to improve conversions of all types, especially acquisition.

Introduced to digital marketers in 2007, this metric doesn’t require leveraging third-party cookies. Instead, it focuses on identifying components of your digital content that prospects find interesting. 

Measuring interest has never been easy. Unlike the other three phases of a conversion, there isn’t an out-of-the-box metric for it. Let’s take a moment to consider the other three.

Back to AIDA

Think about the sales theory you learned way back in a Marketing 101. It showed the four psychological phases of a sale everyone goes through: attention, interest, desire, and action (AIDA).

You can easily measure three of the phases: 

Attention: This is measured by page views. When someone loads a page (or downloads and opens your mobile app), they’ve given you their attention.

Desire: This is measured within a conversion funnel. People at this phase are asking qualifying questions, such as, When can it be delivered, or, What are the payment options? And it’s all trackable!

Action: This is your latest acquisition, and it’s also measurable, either by your ecommerce or subscription system. 

Why is measuring Interest so hard?

Snacking: Visitors Are Quick to Window-Shop 

Part of the answer to that question is content “snacking.” How do you know what content on your site or mobile app is truly interesting to prospects, as defined in the AIDA framework? A key challenge is the customer experience (CX) phenomenon of users visiting, spending some amount of time on your content, then leaving without moving to the Desire phase. 

Do you measure interest by the time users stayed on the page they landed on or the one they spent the most time with before leaving? Attention is way too fragmented to make that determination. 

Think of it as window shopping. Interested visitors may return two, three, or more times to your site. First-party cookies and device IDs don’t help you know this: An example “shopper” may visit initially on a work computer, come back for a second visit on their cell phone, and finally make the purchase on their iPad. So much for clear attribution! 

You’d think bounce rates might help measure the “interestingness” of a piece of content. But sadly, bounces aren’t a trustworthy interest metric for individual pages, again because of snacking. 

Consider this post by Yoast:  

A high bounce rate can mean three things: 

• The quality of the page is low. There’s nothing inviting to engage with.
• Your audience doesn’t match the purpose of the page, so they won’t engage with it.
• Visitors have found the information they were looking for.

Enter Content Interest Index (CII)

CII looks for actions that are proxies of genuine interest. A popular one is measuring the event of revealing hidden sections of your content, such as a table behind a hidden DIV layer or scrolling down. Another is sharing the content via email or social media. 

To calculate CII, these events are each given a score for their level of “interestingness,” and this cumulative score in a given period of time is divided by the Attention metric (page views). 

As you can imagine, this can be a low score – a tiny fraction of 1:1. That’s why it’s an index.

Once you’ve determined that the numbers are indeed large enough to be statistically significant, you can amplify each fraction by a constant multiplier to make the figure more consumable. You can then compare the CII for a page with its same CII from a prior period. 

Because Interest is a necessary link in the AIDA chain, you can then use the increases or decreases in CII of a page to optimize it and other pages for their  ability to convert – the natural conclusion of the chain. 

Did you change or add a photo from one period to another and see CII increase? Think about why that happened and consider adding similar photography to other key pages. Did CII fall? Look back in your CMS at what changed and undo those changes. 

CII isn’t a panacea. You need to use it on pages surrounding conversion funnels, such as Product Description Pages. And you will eventually need to do a statistical analysis to conclude that for your site, CII really is correlated with improved conversions – including acquisition. 

But in a world where there is no better statistical measure of interest, this metric can be a game-changer for your digital marketing.