Why CRO Experts Are Ditching Design for Content—And What That Means for Your Website’s Success

Ever wonder why some ecommerce sites look like a million bucks but just don’t convert? Spoiler: it’s not just about the shiny design. Dave Diederen, a sharp developer-turned-conversion guru from the Netherlands, dives deep into why testing every nook and cranny—from product pages to ads—can unlock growth that mere aesthetics can’t touch. Turns out, folks often sideline their content and copy, but Dave insists that’s where the real magic happens. In our chat, he uncovers game-changing tactics on announcement bars, pricing placement, email pop-ups, and why your home page might be quietly leaking potential sales. If you’re serious about squeezing more conversions out of your ecommerce hustle, you’ll want to stick around for this. LEARN MORE.

Dave Diederen is a Netherlands-based developer turned conversion rate optimization pro. He encourages ecommerce brands to test product pages, ads, and, well, everything.

He says merchants often prioritize their sites’ aesthetics over copy and content, a big mistake. “Content and copy play a very big role in conversions, if not the biggest,” he told me.

In our recent conversation, he addressed conversion wins, product and home page tactics, A/B strategies, and more.

Our entire audio is embedded below. The transcript is edited for clarity and length.

Eric Bandholz: Who are you?

Dave Diederen: I’m the founder of Syntra, a conversion rate optimization agency in the Netherlands. I’m a firm believer in testing and collecting as much data as you can. We do a lot of product page and listicle testing.

I encourage the brands we work with to test new advertising angles, too, such as new creative.

Traffic that doesn’t end up on a product page has no chance to buy. So I tell merchants to keep it simple, focus on what they have, and optimize it.

Bandholz: What is the minimum traffic volume for statistically reliable testing?

Diederen: I would focus on the number of orders, not traffic. A brand might have 100,000 visitors and just 20 orders. There’s no way to judge that data accurately. So I aim for around 250 orders for an A/B test. That’s more than enough.

Brands that do not have 250 orders should typically focus on advertising to increase the volume. Every business is different, however.

Bandholz: Which areas on ecommerce sites drive the biggest conversion gains from testing?

Diederen: Announcement bars are the biggest. Even single-product stores can leverage them well. Most sellers slap on an announcement bar and forget about it. Instead, always link it to a product page, regardless of the promotion. Visitors tend to click on announcement bars.

Another mistake I see is not showing the price under a product title or above the fold in the product page description. Unfortunately, brands often show it in the variant selector or in the add-to-cart button.

If you’re selling supplements, address the ingredients. Comparison charts work well for fashion and healthcare.

Reviews always work well.

Other items are low priorities for conversion. FAQ sections and social proof can go at the bottom of the page, although it depends on the industry.

Brands don’t realize how many visitors divert to the home page. Visitors may start on a product page, click the company logo, and end up on the home page. But most brands don’t optimize their home page. A strong home-page hero image is a good place to start, whether it’s a lifestyle or product image.

Bandholz: How does copy impact conversions?

Diederen: It’s very important, way more than most merchants think. Most focus on a site’s appearance, but trust me, the look and feel aren’t as important. At the end of the day, what matters are the products.

Be specific about your product’s benefits and the problems it solves.

So, yes, content and copy play a very big role in conversions, if not the biggest.

Bandholz: What is your take on email pop-ups?

Diederen: It depends on how many visitors respond. If you get a lot of signups from pop-ups, it makes no sense to remove them. I’ve tested hiding pop-ups for four brands, and it has mostly reduced sales.

So I say don’t get rid of pop-ups, although don’t overdo them either.

Bandholz: Where can people follow you, support you, hire you?

Diederen: Our site is SyntraLabs.com. Follow me on X. I’m also on LinkedIn.