Mattress Firm takes on delivery and setup services for mattress buyers on Wayfair.com.
The retailers topped Internet Explorer and Firefox availability testing, respectively.
HPShopping.com had the best availability score in Internet Explorer testing among large retailers measured in August, says Compuware Gomez. Last month, the retailer posted 100% Internet Explorer availability. Toysrus.com topped Firefox availability rankings at 100%.
Amway.com finished second behind HPShopping.com in Internet Explorer tests with 99.97% availability. Gap.com (99.95%) was next, followed by Overstock.com (99.90%), and CDW.com and OfficeDepot.com (tied at 99.89%).
In Firefox testing, five retailers (Gap.com, HPShopping.com, HSN.com, Overstock.com, Williams-Sonoma.com) tied in second place behind Toysrus.com with a 99.99% availability score for the month.
The average Internet Explorer availability score among the 19 retailers measured in August was 99.55%. The same group of retailers produced an average Firefox score of 99.65%.
Availability is determined by the percentage of tests that load correctly.