Ever mindful of the attentive customer service that online shoppers demand, Geerlings & Wade Inc., the nation's largest direct marketer of wine, recently decided to add a live customer-service feature to its Web site. But early results indicate that the new feature is not a sure thing.

Geerlings & Wade president David Pearce said this week that only 72% of the calls generated by shoppers who click on its live help icon were completed by the call center at its Canton, Mass., headquarters. That compares with more than 98% of calls completed through the toll-free number for its catalog. "We're trying to figure out why it's not higher than that, but it's still a pretty good success rate," Pearce says. Usually, the success rate is higher, although it varies case by case, says Susan Oblak, VP of marketing for WebDialogs Inc., which provides the technology, called WebInteract, to link the call center and online shoppers. Part of the problem, she says, may be that shoppers accessing the Internet from home with just one phone line are confused about having to log off in order to receive the call.

Simply clicking on the "Contact us Live" icon doesn't trigger a call. Instead, a shopper must submit his or her name, phone number, and E-mail address. Geerlings & Wade's customer-service center then automatically places a call within seconds, and the individual is placed on hold until a company representative is available.

But because response depends on total call volume, the wait may become too long for some people, causing them to hang up. And, Web surfing on a single phone line can block incoming calls, so unless surfers disconnect, they won't receive the call.

Another hang-up is that Geerlings & Wade, which sold $5.5 million (15% of its overall sales) online last year, operates its call center only from 7:30 a.m. to 11 p.m. EDT, fielding 850 calls per day. So someone in San Francisco wondering about the finer points of a Zind-Humbrecht Gewurztraminer isn't able to reach someone after 8 p.m.

Geerlings & Wade puts the WebDialogs contact button on 10% of its pages, primarily on those for ordering and customer service.