The chain trims 1.5 seconds off its mobile site load time, but errors arise.

Page load time and site availability (also known as success rate) together make up mobile commerce site performance on the Keynote Mobile Commerce Performance Index. Both are equally important in measuring how a mobile site performs for consumers on smartphones.

Last week, Best Buy Co. Inc. went in two different directions with mobile site performance: load time improved while success rate suffered. The merchant cut its m-commerce home page down in size, from 600 kilobytes to under 300 kilobytes, in the process trimming 1.5 seconds off of its page load time, Keynote says. For the week ending June 16, Best Buy’s m-commerce site home page load time was 10.82 seconds. The quickest load time was 2.12 seconds and the index average load time was 10.43 seconds.

But Best Buy’s mobile site was plagued by connection errors on the AT&T and Verizon wireless networks, and as a result, its success rate was only 97.86%, Keynote says. A connection error occurs when a mobile web browser cannot connect to the mobile site.

“There are several types of connection errors,” explains Abelardo Gonzalez, mobile performance evangelist at Keynote. “It could be the way the carriers are sending the data to the Best Buy servers or an issue at Best Buy where they are dropping data packets. It’s one of the most frustrating types of errors because it is hard to pin down with certainty. But last week, the success rate of all retailers on the index went down, so it could definitely be an issue with AT&T and Verizon not making successful connections.”

Best Buy did not respond to a request for comment.


Sears Holdings Corp. topped the index with a load time of 2.12 seconds and a success rate of 99.01%. Weighting and then combining load time and success rate earned Sears an index score of 999 out of 1,000. Inc. came in second with a load time of 6.72 seconds and a success rate of 99.01% for a score of 946. And Barnes & Noble came in third with a load time of 5.18 seconds and a success rate of 98.78% for a score of 936.

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 Inc. to midsized retailers like 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.


Keynote is ranked No. 2 among web performance monitoring firms in Internet Retailer’s Leading Vendors to the Top 1000 E-retailers guide.