Ecommerce sites for major retailers are being torpedoed by iPhone ad-blockers, with content missing – in some cases, the entire site does not show up ­– broken links and non-functioning shopping carts, casting a pall over mcommerce sales just as the holiday season is heating up.

Mobile Web site developer Branding Brand first reported that ecommerce sites for Walmart, Sears, Lululemon and others are not fully rendering on iPhones enabled with content-blocking app Crystal, with business magazine Fortune later replicating the experience. Even when sites are rendering, the banners for complementary products used by many retailers use are not showing up.

“Potentially [this news is] enormous,” said Scott Allan, head of marketing at Pure Oxygen Labs. “The ad tech ecosystem has been built on the idea that implementing technologies related to personalization and retargeting is incredibly easy.

“Retailers have built their site operations and analytics around these easy-to-use javascript and cookie-based technologies,” he said. “In one fell swoop the ad blockers are wiping out the investment retailers have made in personalization and retargeting over the last several years.

“Even if the site can function properly with an ad blocker enabled, there’s still a potential for a huge negative impact on sales.  Marketing departments will also have less data to work with in making merchandising decisions.”

Sales impact
Content-blocking software has only recently become available on iOS with Apple’s launch of the operating system’s latest update last week. However, has been gaining steam on Android and desktop for some time.

While much of the focus of ad-blocking coming to iOS has been on what the impact will be on advertisers and publishers who make money off of digital ads, it is becoming clear that other marketing-related content could be impacted as well.

The problems encountered by Branding Brand and Fortune include product images not showing up, the entire site not rendering, being unable to add products to the shopping cart.

In Mr. Allan’s own experience, the sites rendered but with some content missing.

“In my own experience, using the ad-blocker Crystal for example, the Macy’s site works properly but the banners for complementary products are removed,” Mr. Allan said. “Sears in a similar way promotes ‘Sponsored Products’ in banners within the different product sections and these are also removed when the Crystal ad-blocker is enabled.

“Best-case scenario is that shoppers using ad blockers may click through fewer products as a result of personalized and complementary selling and ultimately the impact may be lower AOV.”

Time to recode
The issues uncovered mean that consumers will have a harder time buying gifts from their mobile devices this holiday season. The news comes as the mcommerce sales are growing, with a significant percentage of this activity taking place on iPhones.

One problem for retailers is that if consumers have a less-than-optimal experience, they may just go to another retailer’s site, possibly to never return.

The content blockers will also reduce retailers’ ability to collect data that can help them optimize and personalize the experience.

To address these issues, retailers should audit their site in relation to the user experience and these various ad-blockers, which could end up being a big undertaking.

With the holiday season quickly approaching, retailers may need to work quickly on any recoding that is needed to insure consumers are able to shop their sites from mobile.

“At the very least, they need to make sure the site is visible and the user can check out,” Mr. Allan said. “Then it’s a matter of understanding what technologies are making the site vulnerable to a disruptive user experience when an ad-blocker is enabled and trying to mitigate that.

“In addition, a white-label or alias strategy for various technologies could also potentially be implemented which would embed the technology or solution in the retailers domain,” he said. “So this turns into an intelligent routing and mapping exercise but also depends on each technology vendor and their ability to operate in an alias or white label mode.

“Given the number of technologies in the ecosystem this can get very complicated very quickly.”

Possible silver lining
The developers of the ad-blocking apps may also be open to making adjustments that address some of these issues for retailers, however it is still not unclear how effective anything they might do would be.

“The silver lining in all this is that ad-blockers may get limited market penetration,” Mr. Allan said. “Many consumers have gotten used to relevant, personalized content and may not want to give up that experience for something more generic.”

Final Take
Chantal Tode is senior editor on Mobile Commerce Daily, New York