If you like speaking with live customer service reps about service issues without having to first endure a long and frustrating wait on the phone, then shop at Sierra Trading Post. That is one conclusion that can be drawn from a study of online retailers released by StellaService, which found that the retailer made customers wait on hold for just six seconds, on average, before a live rep came on the line. That is the shortest average time of the 100 Internet retailers studied in the survey.