NEW YORK (MainStreet) – Back-to-school season is upon us, and we won’t blame you if you want to shop online to avoid the crowds. But if you’re looking for good customer service, some sites are better at it than others.

STELLAservice, a research group that rates e-retailers’ customer service, looked at the big companies for back-to-school shopping and assessed how easy it was to buy and return items. Its conclusion? If you’re looking for ease of use, timely delivery and hassle-free returns, your best bet is Costco. was the only “one-stop shop” online retailer to score positively in each of the six metrics researchers used to determine which retailers provided the most hassle-free experience. The site allows alternative payment methods beyond credit cards, provided an estimated delivery date and tracking number for the shipment, delivered within three days, had an easy return policy (defined as not requiring return authorization before making a return) and a return window of 90 days or more (Costco has a 90-day window for electronics and an unlimited window for everything else). was the only retailer to score even five out of six points, getting dinged for its slow delivery time.

In addition to its clean sweep of the “hassle-free” categories, Costco was also number one when it came to delivery time. On average, packages ordered from arrived in just a day and a half; by contrast, took 5.5 days to deliver the goods, among the worst of the one-stop shops.

While STELLA didn’t deem any retailer the worst of the bunch, it’s worth noting that only one online retailer flunked four of the six categories: According to the survey, Meijer provided neither timely delivery nor an estimated delivery date, does not accept alternative forms of payment like PayPal and doesn’t have an easy return policy.

Of course, it’s worth noting that Costco is the one retailer on the list that requires a paid membership to shop at, so perhaps it’s to be expected that it would go above and beyond for its members. And that brings up another point that shoppers should keep in mind: The rankings don’t account for price, so it’s important to shop around and see if Costco is providing the best price for your targeted items even when the cost of membership is taken into account.

If a retailer like Amazon turns out to provide more bang for your back-to-school buck, you’ll have to consider whether slightly faster delivery and a more generous return window is worth paying a premium.

For all your deals and tips for the back-to-school shopping season, check out MainStreet’s back-to-school coverage.

—For the best rates on loans, bank accounts and credit cards, enter your ZIP code at