Dive Brief:

• Best Buy, The Home Depot and Target have the highest-ranked mobile web user experience of eight major retailers evaluated in the Retail Mobile Customer Experience Index published this week by UserTesting, the company announced at the Internet Retailer Conference & Exhibition in Chicago.

• Costco and Walmart received the lowest rankings of the retailers evaluated, though UserTesting said in a statement that scores for all retailers involved were “fairly high.” Macy’s and TJ Maxx, the other two retailers studied, finished in between the top three and the bottom two.

• The UserTesting study asked 800 consumers to evaluate the retailers' mobile web sites based on five factors — ease of use, speed, credibility, aesthetics and delight. Retailers that performed well provided an appropriate amount of information throughout the shopper journey without requiring much effort from the customer, the company said, while companies that made the buyer journey more frustrating were rated lower.

Dive Insight:

Best Buy reported very strong first quarter financial results at the end of May that included, among other things, a 22.5% increase in online sales in the U.S. At that time, the retailer said that improving conversion rates were leading to online sales growth, and helping online represent a larger portion of its total sales.

What led to the higher conversion rates? Maybe it was, at least in part, Best Buy's ability to offer a high-quality mobile web site user experience for shoppers visiting via smartphone. In any case, the results of the UserTesting evaluations would seem to back up that argument.

Brian Smith, vice president of marketing at UserTesting, noted that both Best Buy and Home Depot have heavily invested in omnichannel efforts that require a strong mobile user experience. “We have entered what Forrester [Research] calls 'the age of the customer,' in which retailers must develop a deep understanding of what their customers value most and deliver superior digital experiences — or risk becoming irrelevant,” Smith said in a statement announcing the test results.

Meanwhile, UserTesting seemed to let Costco and Walmart off the hook for finishing at the bottom of the list, saying that actually all the retailer's scores were fairly strong, but finishing at the bottom of this particular grouping of customers is in no way a positive development for either retailer. Each might want to review the results more closely to see what users feel their mobile experience are lacking. Costco, for example, scored poorly for the ability of users to simply find particular products on its site — a very big problem for a retailer to have in the mobile commerce era.

The five factors the retailer sites were graded on range from the fundamental to esoteric — for example, delight?The consumers who performed the evaluations may have had no better idea what delight meant either, as it was UserTesting's "most elusive factor" and the one that scored lowest across the board. The more fundamental areas, such as ease of use and speed, are the factors to really pay attention to. It has become clear in the last year or so that retailers need to work on improving overall performance of their mobile apps and shopping experiences.

Mobile has become an important tool in offline shopping, but if retailers want it to be more than that, they have to eliminate instances in which poor usability and slow performance drive shoppers away.