The latest stats from Web performance tracker Gomez show some of the faster sites (including QVC and Amazon) sometimes delivering speeds 13 times faster than what their slower counterparts (including Target, HSN and Netflix) are delivering. In April, for example, QVC had an average response time of 2.2 seconds, while Netflix delivered 28.6 seconds. In May, QVC scored 1.5 seconds to Netflix's 11.3 seconds and Office Depot's 8.5 seconds. In June, QVC was clocked at 2.3 seconds and Amazon at 4.6 seconds, compared with Wal-Mart at 9.7 seconds, Target at 9.6 seconds and HSN at 10.8 seconds.
The explanations for the sharp differences are many, with some sites simply not trying, in the sense that their "mobile sites" are simply their regular Web sites as seen through a mobile browser. Still, from the customer's perspective, that's a fair comparison because it reflects what the customer will likely experience.
But one of the biggest slowdowns, according to Amir Rozenberg, a product manager at Gomez, is something designed to actually facilitate mobile performance: redirects. Many mobile sites try and get sophisticated and deliver a highly customized— and hopefully optimized— experience for shoppers. That might mean detecting the customer's geography, mobile platform (and sometimes even more granular details, such as "different experiences based on the different versions of the iPhone") and cookie-based preferences, in addition to delivering the best version of the site. "I've seen mobile sites with six or seven redirects," Rozenberg said.