Until now, the average e-retailer’s idea of customer service was to offer an e-mail link and dump customer inquiries into the e-mail queues of a few staffers working in the back office.

That model is costing e-retailers serious bucks: A recent Datamonitor report says Internet retailers lost $6.1 billion in sales last year as a result of poor online customer service — a figure that could skyrocket this year.

Customers expect on-time delivery, and they want instant service gratification — or they’re likely to click away. Today’s online shoppers expect the same customer service they get at traditional retail stores — a clerk to answer questions and real-time assistance in finding products and delivery and fulfillment information before they make a purchase.

To respond to these ever-expanding customer demands, vendors now offer many service technologies that go way beyond e-mail: automated e-mail management, instant messaging, Web call-back and even voice-recognition software that lets off-line shoppers buy online via the telephone.

A growing number of e-retailers are jumping in — and it’s not just customer service leaders like Lands’ End and SmarterKids.com.