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The Goals

  • Drive traffic to and generate awareness for the Samsung Galaxy S5
  • Serve HTML5 creatives to all available inventory
  • Target tech-savvy consumers on all devices

The Approach

  • Use HTML5 to create compelling mobile-friendly ads
  • Control HTML5 file size with Google Fonts and sprite sheets
  • Use DoubleClick Campaign Manager to target users of competing service providers in all regions

The Results

  • HTML5 impressions had a 1.1% backup rate, 85% lower than the flash creative backup rate
  • HTML5 smartphone ads equaled or outperformed Flash desktop ads in key conversion categories
  • Mobile creatives outperformed desktop creatives with a CTR over 400% that of desktop


Published October 2014

The bright magenta of T-Mobile ads stands for more than great phone service; it stands for innovation. This ambitious wireless company is the “un-carrier”—the company is working to change wireless for the better. Their industry-leading moves include eliminating limits and domestic overages with their Simple Choice plan, and getting rid of the hated annual service contract. T-mobile allows customers to upgrade at any time and will even pay for customers’ ETFs if they are stuck in contracts with other carriers. 

When it came time to showcase another game-changer, the powerful new Samsung Galaxy S5 phone, T-Mobile turned to the DoubleClick Digital Marketing platform and the cutting-edge user experience of HTML5 ads.

Making a leap forward

T-Mobile and its agencies, Publicis Seattle and Optimedia, knew that HTML5 would solve the big shortcoming of the standard Flash ad format: mobile reach. “As a digitally driven agency, we’re always testing new platforms, methods and processes to remain at the forefront,” says Nelson Fortier, Sr. Manager, Marketing & Development at Publicis Seattle. “And as a challenger brand, T-Mobile was the ideal partner.”

Flash has been the animation standard for many years, but it won’t render at all on mobile; instead of the rich animation, a backup static image gets served to smartphones and tablet devices. With over 25% of all global web usage occurring on smartphones or tablets* that's a bad experience for both users and advertisers. 

HTML5 is a universal language that renders rich media ads on smartphones, tablets and desktops alike. T-Mobile knew if they adopted HTML5, they could make a major improvement to their campaign reach.

We thought that HTML5 could give us a true ‘one language fits all ’solution. We’d also no longer need different assets for
desktop and mobile, and that would give us a big savings on creative.

Nelson Fortier, Sr. Manager, Marketing & Development, Publicis Seattle.

And as a cutting-edge mobile provider, it was fitting that T-Mobile might create a cutting-edge brand experience for mobile ads.

Reaching all devices

Publicis Seattle worked with DoubleClick to build a Samsung Galaxy S5 campaign that would target tech-savvy consumers on many devices. Thanks to the targeting capacities of DoubleClick Campaign Manager, Optimedia was even able to target users of competing mobile providers, to try to get them to switch T-Mobile. 

Since HTML5 files tend to be large, one obstacle for developers is staying within the file size limits of most publishers. Publicis Seattle first used a process called “minifying” to remove unnecessary characters and white spaces from the code. Since using many images to generate animations also adds weight, Publicis developers inserted a sprite sheet: a single image containing all of the graphic elements on it. They then used CSS to display each graphic separately, across all keyframes, for a richer experience.

Another challenge: fonts. Most brands use generic web fonts when coding HTML5, because custom fonts require an image for each character and that adds up to bigger file sizes. Yet T-Mobile, like most brands, legally needs to use its own licensed font in all their ads. It was a problem that couldn’t be ignored.

Here DoubleClick and Google came to the rescue. The DoubleClick team hosted the T-Mobile font on Google Fonts where subsets of the font characters could be dynamically loaded as if they were a standard web font. Working with the URW++ font foundry, the T-Mobile team became the first brand in history to load its custom font into Google Fonts. This streamlined process created a fast-loading ad with a small file size.


T-Mobile’s ads (yes, in bright magenta) for the Samsung Galaxy S5 were a success. The campaign results confirmed the power of HTML5 across the board:

  • HTML5 ads reached users on mobile. HTML5 brought T-Mobile’s rich media ads to the 25% of all web traffic that happens over mobile devices. 
  • 1.1% backup rate on HTML5 impressions. This was an impressive 85% lower than the Flash creative backup rate of about 7.3%.
  • Mobile CTR was 400% that of desktop. While mobile devices can show more accidental clicks, the team believes this improved result was due mainly to HTML5 providing a more richly engaging experience for more mobile users.
  • HTML5 smartphone ads equaled or outperformed Flash desktop ads in key conversion categories. Once on, users who had clicked on HTML5 smartphone ads were just as likely or more likely than Flash desktop users to explore content, interact and show an intention to purchase.
  • Serving fees were lower. “HTML5 uses cloud technology, so its file sizes are much smaller than Flash,” says Nelson Fortier. “This results in lower ad serving fees, saving T-Mobile valuable media dollars.”

Armed with these powerful results, T-Mobile and Publicis Seattle have begun using HTML5 for other DoubleClick campaigns.

“We saw a huge difference with HTML5 compared to similarly-targeted flash banners,” says Nelson Fortier of Publicis Seattle. “It’s compelling proof that with HTML5 and DoubleClick, T-Mobile’s reach on both desktops and mobile devices far eclipsed that of Flash-based ads.”


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