Free Trial

How Curiosity Media Solved Troubling Mobile Redirect Issues for

Download the PDF  Try cleanAD for Free



“The cleanAD team is truly solving the unsolvable, and as such, we consider them one of our most valuable partners.”

→ Lauren Hefferon, Product Manager at Curiosity Media

spanishdict phone mobile


About Curiosity Media

Curiosity Media is the team behind the leading Spanish learning websites, SpanishDict and Fluencia, which collectively help more than 100 million people each year with reliable, accurate, easy-to-use resources for speaking Spanish. is the world's top destination for Spanish language reference and learning materials for millions of students every year. The website’s most-loved features include millions of free, high quality dictionary translations, conjugations for every Spanish verb, and real-time comparisons of sophisticated translation engines.

A Dedication to Quality

As a publisher that serves the education market, including cases where the site may be used in classroom settings for students, surfacing only top quality ads is a high priority for the Curiosity Media team.

The team has always had great success containing “ad quality” by working directly with SSPs to implement strong category blocks and building unique rules for allowances of ads. For instance, they found that blocking certain types of ads at specific CPM ranges allowed them to effectively keep some categories of ads out of classrooms.

The team prides itself on maintaining a heavy degree of control over ad quality, and a strong understanding of how to build creative rules that allow the perfect mix of ads for their users.

However, one specific problem still plagued them: malvertising.


“We’ve found that while we have no trouble staying in front of ad quality, we really struggled to stay a step ahead of malicious ads.”

Lauren Hefferon, Product Manager at Curiosity Media

Large Footprint, Lean Operation is a top 100 website in the US, so it commands a very large footprint.

As a relatively small organization, Curiosity Media’s AdOps team was running some hefty websites on very limited engineering resources. 

The team had access to two engineers, but was only able to utilize them for AdOps requests about half the time. This meant that they had to be laser focused, and very picky, about what those engineers spent their time on.



“As a lean operation, we have to be very careful with the activities we rely on our engineering team to execute, knowing that we won’t have access to them 24/7.”

Lauren Hefferon, Product Manager at Curiosity Media

Solving the Malvertising Dilemma

For, malvertising reared its ugly head primarily in the form of malicious redirects. In late 2018, the Curiosity Media team was fighting user complaints about redirects, and working to remedy the frustrating user experiences that they caused.

They found that their engineering team simply didn’t have the resources to try and keep up with the constantly changing tactics employed by malicious actors. Every time they tracked down a bad actor, the delivery methods or attack types would change. 

It became clear, as larger and more frequent malvertising attacks were hitting the publisher, that using their engineering resources to manually trace and turn off campaigns was not sustainable. 

They were playing a losing game, and needed a better solution.



“Repeat users who fell victim to attacks would submit complaints, but what really concerned us was the 10, 100 or 1,000 other users who were potentially experiencing attacks and simply choosing not to return to our site.”
Lauren Hefferon, Product Manager at Curiosity Media
CTA-Background (1)

Testing a Solution

The Curiosity Media team was confident that they needed a third party solution that specialized in malvertising prevention to help solve the problem. They chose to run a free trial of cleanAD to verify that it met their requirements.

The team was specifically concerned with ensuring that both ad reporting and ad serving continued unaltered and uninterrupted from the current state. The Curiosity team was most attracted to cleanAD because of two primary features that helped to ensure this very thing:

  1. No Reduction in Ad Revenue: Because cleanAD allows creative to render, but stops the malicious action from executing, malvertisers still have to pay for impressions (leaving ad dollars intact) but users aren’t affected by malicious code.
  2. No Maintenance: The simplicity of the cleanAD integration, and the fact that it blocks malicious ads more effectively than other solutions, with no manual intervention required, was especially important for the bandwidth-constrained engineering team.


“Preserving ad dollars and ad reporting was our number one priority. cleanAD was able to prove during the free trial that we would never have to sacrifice revenue when choosing to block malicious ads.”

Lauren Hefferon, Product Manager at Curiosity Media

Living the Good Life

Since implementing cleanAD on mobile web, the Curiosity Media team has been able to pretty much forget about malvertising and malicious redirects in that channel. The problem has completely stopped.

Rather than simply providing software, the team at works regularly with the AdOps team at Curiosity Media to provide regular monthly reporting along with important insights to help them improve operations.

In addition, has seen measurable improvements in a few key areas:

  • User satisfaction has increased
  • The volume of ad complaints has dropped precipitously
  • User engagement metrics have increased


“The best part about cleanAD is that it has worked almost seamlessly since the day it was set up.”

- Lauren Hefferon, Product Manager at Curiosity Media

In fact, since implementing cleanAD, has seen an 80% increase in monthly page views per user. While we can’t take full credit (the incredible content produced by is also a huge driver of engagement), this increase can be at least partly attributed to better user experiences and reduced frustrations, both of which have helped to decrease visitor churn from the site.

In the year since cleanAD has been running, the Curiosity team has seen only two instances of bad ads striking its protected traffic. In both cases, they were entirely new attack types hitting the industry very hard as a whole, and both were identified and stopped immediately.



“cleanAD is truly a maintenance-free solution. We added the script on our pages and that’s the end of the story. It has performed exactly as advertised.”
Lauren Hefferon, Product Manager at Curiosity Media

Ready to learn more?

Start your free trial. Stop chasing redirects.

  1. Simple to install, a single line of code.
  2. 24x7 dedicated client success and technical support.
  3. Full access to on-boarding, training materials and analytics dashboard.

14 days free  ●  Easy set-up  ●  Get started today