Home Data-Driven Thinking File Size: A Common Mistake That Could Be Killing Your Display Ad Effectiveness

File Size: A Common Mistake That Could Be Killing Your Display Ad Effectiveness

SHARE:

Data-Driven Thinking” is written by members of the media community and contains fresh ideas on the digital revolution in media.

Today’s column is written by Ian Hewetson, vice president of client services at Eyereturn Marketing.

Fraud and viewability get all the attention when marketers question their display ad effectiveness. But there’s a more common issue that dilutes the reach of billions of ad impressions every day: file size. And it’s so much easier to solve than either viewability or fraud.

When Flash suddenly died, designers struggled to produce the same kinds of ads clients were accustomed to at low file size. Ad-serving platforms adjusted specs to accommodate the new reality. Where the file size of a standard ad used to be capped at 40 kilobytes, the new ad-server allowance was expanded to 300 kilobytes – a 650% increase.

And while this may seem like no big deal when we’re talking about a single ad, once there are five ads on a page, this extra file size starts to add up, especially if several of the ads are at the limit. Keep in mind that real-world download speeds are far lower than what you might expect.

Bloated file sizes also compromise viewability. As users load a page and start scrolling down, any ad that is considered to be viewable must be properly positioned and loaded to meet the standard. If the ad is taking too long to load, it’s more likely to be nonviewable.

This hurts advertisers who want to get their message in front of users. But it also hurts publishers that are trying to deliver and get paid for a high percentage of viewable ads. At least the advertiser has some control over the file sizes of their ads, but publishers running third-party tags often have no visibility into ad file sizes.

The problem becomes a perfect storm on mobile. Slower connection speeds mean longer load times. Smaller screens also mean faster scrolling. Unless the ad is anchored to the bottom of the screen, the chances of it being seen become seriously diminished.

Ads often are needlessly designed at the limit. An ad with a smaller file size is more likely to render before the user scrolls away. If a user scrolls away before seeing an ad because the designer went to the file size limit, that opportunity to connect with the consumer is lost no matter how sharp it might look.

And all too often GIFs and JPEG files are delivered at a larger file size than necessary. For the standard IAB ad dimensions, a JPEG is often going to be at its highest image quality at around 80 kilobytes. Beyond that, an ad is not going to look any prettier to the human eye.

Some large file sizes for complex or interactive HTML5 ads could be considered justifiable, of course, since these ads may need a large file size to function properly.

Subscribe

AdExchanger Daily

Get our editors’ roundup delivered to your inbox every weekday.

To be sure, there are a ton of other variables that contribute to page latency and the chance that a user won’t see an ad. These include the weight of the page, the method of delivering the ad into the page, the power of the user’s processor or browser type, to name a few. The list is almost endless, and much of it is outside of the advertiser’s control.

But given that file size is one of the few variables that advertisers do have 100% control over, they should start exercising strict oversight. And soon, LEAN standards will start to gain traction and systems like The Washington Post’s Zeus will put speed into the spotlight.

The bottom line is that everyone wants their ads to look as good as they can. But if marketers build their ads to the limit of file size rather than optimizing them for the lightest weight, it’s like approaching the finish line of a race and stopping to pick up a couple of dumbbells for the last 10 yards.

Follow Eyereturn (@EyereturnMktg) and AdExchanger (@adexchanger) on Twitter.

Must Read

Jamie Seltzer, global chief data and technology officer, Havas Media Network, speaks to AdExchanger at CES 2026.

CES 2026: What’s Real – And What’s BS – When It Comes To AI

Ad industry experts call out trends to watch in 2026 and separate the real AI use cases having an impact today from the AI hype they heard at CES.

New Startup Pinch AI Tackles The Growing Problem Of Ecommerce Return Scams

Fraud is eating into retail profits. A new startup called Pinch AI just launched with $5 million in funding to fight back.

Comic: Shopper Marketing Data

CPG Data Seller SPINS Moves Into Media With MikMak Acquisition

On Wednesday, retail and CPG data company SPINS added a new piece with its acquisition of MikMak, a click-to-buy ad tech and analytics startup that helps optimize their commerce media.

Privacy! Commerce! Connected TV! Read all about it. Subscribe to AdExchanger Newsletters

How Valvoline Shifted Marketing Gears When It Became A Pure-Play Retail Brand

Believe it or not, car oil change service company Valvoline is in the midst of a fascinating retail marketing transformation.

AdExchanger's Big Story podcast with journalistic insights on advertising, marketing and ad tech

The Big Story: Live From CES 2026

Agents, streamers and robots, oh my! Live from the C-Space campus at the Aria Casino in Las Vegas, our team breaks down the most interesting ad tech trends we saw at CES this year.

Monopoly Man looks on at the DOJ vs. Google ad tech antitrust trial (comic).

2025: The Year Google Lost In Court And Won Anyway

From afar, it looks like Google had a rough year in antitrust court. But zoom in a bit and it becomes clear that the past year went about as well as Google could have hoped for.