Achieving optimal mobile performance requires ‘good housekeeping’

After the holiday rush, Best Buy’s m-commerce site was still programmed to include a holiday deal image—but the image no longer existed on the merchant’s servers. That created problems that could have been avoided, Keynote says.

Bill Siwicki

Best Buy Co. Inc. was a little forgetful in the weeks after the hectic holiday shopping season, and its forgetfulness caused shoppers accessing its m-commerce site on a smartphone to have a less than stellar mobile shopping experience, says mobile and web performance testing, monitoring and analytics firm Keynote.

During the holidays, the Best Buy mobile commerce web site’s home page included an image promoting special holiday deals. The retailer removed the image file, titled Deal.png, but did not change the site to cease requests for Deal.png; that led to content errors that created problems during page loads, Keynote says. What’s more, for the week ending Jan. 19 compared with the week ending Jan. 12, Best Buy increased the number of elements (such as images or scripts) on its mobile home page from 23 to 27 and increased its home page’s weight from 256 kilobytes to 309 kilobytes—more elements and more kilobytes means more time required to completely load a web page, Keynote says. The firm advises retailers wanting optimal performance to limit mobile page elements to 10 or 12 and limit page weight to 100 kilobytes or less.

“The Best Buy issues point to the need for good housekeeping around site performance, especially after the holiday rush,” says Venkatesh Giri, Keynote mobile commerce lead. “The lesson is always make sure content errors are identified quickly so they can be fixed just as quickly.”

The content errors, additional page elements and increased page weight caused Best Buy to plummet 17 spots to No. 24 on the 30-retailer Keynote Mobile Commerce Performance Index. For the week ending Jan. 19, Best Buy’s m-commerce site home page loaded on average in 6.99 seconds, which is better than the index average of 8.98 seconds; however, site availability registered at 98.24%, below 99%, which is the minimum percentage for good mobile site performance, Keynote says. Weighting and combining load time and site availability (also known as success rate) earned Best Buy a Keynote index score of only 483 out of 1,000.

Best Buy, No. 24 in the 2014 Internet Retailer Mobile 500, did not respond to a request for comment.

“Retailers should monitor their mobile pages and web developers should always check for missing elements or rogue code references to elements not present on the server,” Giri says. “Removing content errors improves page load times by decreasing the number of server requests, allowing other objects to render quickly.”

Sears Holdings Corp. topped the Keynote Mobile Commerce Performance Index for the week ending Jan. 19. Its load time was a swift 3.14 seconds and its success rate was 99.36% earning it a score of 884. The Sears m-commerce home page contains only seven page elements and is a slim 61 kilobytes. Rakuten.com Shopping came in second with a load time of 3.77 seconds and a success rate of 99.21% for a score of 833. The Rakuten.com m-commerce site home page contains 10 elements and weighs 57 kilobytes. And J.C. Penney Co. Inc. came in third with a load time of 5.19 seconds and a success rate of 99.31% for a score of 826. The J.C. Penney mobile home page contains 15 elements and weighs 157 kilobytes.

Click here then click on Keynote Mobile Commerce Performance Index Part 1 and Part 2 to view complete results for all 30 retailers on the index. Keynote measures, exclusively for Internet Retailer, 28 standalone m-commerce sites optimized for smartphones and two responsive design sites, which are single sites that render content in ways that fit the screen size of a device, including desktop PCs, tablets, smartphones and smart TVs. For the index, Keynote measures the smartphone versions of the responsive sites.

The 30 representative sites include merchants in multiple categories and channels, and of multiple sizes, ranging from such giants as Amazon.com Inc. to mid-sized retailers like Toolfetch.com LLC. Keynote tests the sites in the index every hour Monday through Sunday from 8:00 a.m. through midnight EDT, emulating two different smartphones on two different wireless networks: Apple Inc.’s iPhone 5 on AT&T and the Samsung Galaxy SIII on T-Mobile, both using 4G networks. Keynote runs the tests in New York and San Francisco.

Keynote combines a site’s load time and success rate, equally weighted, into a single score. Given that both performance and availability are important, the score reflects the overall quality of the home page; a higher score indicates better performance. Scores also reflect how close sites are to each other in overall quality. The index average score is the midpoint among all the sites’ scores. To consistently rank high on the Keynote index, sites must hit availability targets of 99.5% or better and be faster than 10 seconds to load on average. Top-performing sites load in under five seconds.

While adoption among U.S. consumers has been steadily rising, only a fraction of all U.S. wireless connections are 4G. Consequently, retailers benchmarking their mobile commerce site performance against the Keynote index should keep in mind that most of their m-commerce site shoppers will experience page load times slower than those on the index.


Best Buy, content errors, Keynote, m-commerce, m-commerce site, m-commerce site performance, mobile commerce, performance, Sears, Venkatesh Giri