The content versus performance tradeoff

HSN adds a slick feature to its mobile site but pays a price, Keynote says.

Bill Siwicki

More features and functions on a mobile commerce web site means more time for pages to load completely. HSN Inc. added a graphical interface element to its m-commerce site home page last week, a move that added 2.79 seconds to the page’s load time, according to the Keynote Mobile Commerce Performance Index.

For the week ending Jan. 13, HSN’s mobile home page loaded on average in 9.20 seconds and did so completely and successfully 99.12% of the time, the index says. The weighted and combined load time and success rate earned HSN an index score of 700 out of 1,000. For the week ending Jan. 6, HSN’s load time was 6.41 seconds and its success rate was 99.56% for a score of 857. HSN dropped seven spots to No. 15 for the week ending Jan. 13.

“HSN has incorporated the FlexSlider toolkit from WooThemes to present an image slideshow,” says Joe Flake, mobile and web performance expert at Keynote Systems Inc. “This provides customers with an easy way to flip to images of popular categories or specials. It’s attractive and uses the swipe motion that smartphone users expect, but does carry some performance impact. In addition to the JPG images, the slider toolkit requires a style sheet, JavaScript for the slider and the jQuery JavaScript library. The page is designed so that other components display before the slider, and then the slider is added with the initial image. These components are cached, so thankfully returning visitors don’t pay the full download penalty.”

The jQuery JavaScript library is a collection of coding designed to simplify and quicken web programming.

Mobile web site developers must keep in mind there are always tradeoffs to be made between page complexity and performance, Flake adds. “On average, HSN is still maintaining a small and fast-downloading mobile web site, but it now includes more complex structures, costing some time in download performance,” he says.

HSN, No. 14 in the Internet Retailer Mobile 400, did not immediately respond to a request for comment.

Office Depot Inc. topped the Keynote index for the week ending Jan. 13. It had a load time of 2.86 seconds and a success rate of 99.76% for a score of 971. Barnes & Noble came in second with a load time of 4.93 seconds and a success rate of 99.88% for a score of 951. And Rakuten Buy.com came in third with a load time of 4.68 seconds and a success rate of 99.76% for a score of 931.

Office Depot is No. 65 in the Internet Retailer Mobile 400. BarnesandNoble.com Inc. is No. 31 and Rakuten Buy.com is No. 30.

The index average load time was 9.08 seconds, the average success rate was 99.26% and the average score was 732.

Click here and then click on Keynote Mobile Commerce Performance Index Part 1 and Part 2 to see this week’s complete results for all 30 retailers on the index.

Keynote Systems measures 30 representative m-commerce sites exclusively for Internet Retailer. The sites include merchants in multiple categories and channels, and of multiple sizes, ranging from such giants as Amazon.com Inc. to midsized retailers like Toolfetch.com LLC. Keynote tests the sites in the index every hour Monday through Sunday from 8 a.m. through midnight Eastern time, emulating three different smartphones on three different wireless networks: Apple Inc.’s iPhone 4 on AT&T, the HTC Evo on Sprint and the Droid X on Verizon. The HTC Evo and the Droid X run Google Inc.’s Android operating system. 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.


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