Digital Advertising for Clinical Trial Patient Recruitment, Part 5

Henning Semat, Head of Online Marketing
Henning Semat, Head of Online Marketing

The Digital Ad Mix: Search engine vs. Display advertising

As digital advertising specialists, getting the digital advertising mix right is essential to our job.  This post focuses on one question we are continually asked when discussing the optimal channels for clinical trial patient recruitment. Although digital marketing solutions have rapidly evolved over our 10 year history, one lingering industry-wide perception believes that digital clinical trial patient recruitment is fueled by search engine marketing.

While search engine marketing was widely used in the early days of digital clinical trial patient recruitment, it now represents a much smaller percentage of the digital mix.  Effective recruitment relies on a broad range of networks and platforms that optimize display advertising. Consider the tactical ad mix from a recent global study below.


Digital advertising mix from a recent Clariness project
Digital advertising mix from a recent Clariness project

The fundamental difference between the two tactics is that search engine marketing focuses on self-directed consumer activity while display advertising targets audiences based on consumer traits.

Search engine advertising allows for the precise targeting of your intended audience by showing a text ad above, or next to the results of specific keyword searches. While the opportunity to match ads to an audience who is actively searching on related topics doesn’t get more precise, the search volume for trial-related keywords is typically too low to generate sufficient responses, and the cost per referral is higher for SEM than other forms of digital advertising. That means you have to tap into groups of people who aren’t necessarily looking for clinical trials.

Display advertising uses broader means of targeting through demographic traits (e.g., age, gender), geography (specific user locations) and topics of interest, using banner ads which combine graphics with a succinct call to action.

Based on our experience, the practice of casting a wide net using demographic targeting generates the best outcomes. Using the example of a diabetes trial, it’s not enough to only target people who are actively looking for information to improve their condition. Even more important is the need for display ad placement beyond healthcare sites. Many referrals come from non-healthcare websites, with significant representation from gaming, news and even celebrity gossip sites. The cost per referral, (with variation across countries) is typically much lower with non-healthcare sites.

You can also use demographic targeting together with other targeting options, such as in-market audiences and remarketing lists (more on this topic in blog 3) for more precision. Of course, the mix also needs to be customized on a country-specific level, but that’s a topic for another blog post.