The worst biggest companies are failing customers by having poor online service according to a new survey.

The Customer Respect Group has complained that only six of the largest 100 US companies achieved "excellent" ratings for online customer service. Another 29 companies received "good" ratings, while 65 companies got failing grades.

The average customer respect index last year was 6.2 (out of a possible 10), while the most recent study showed an overall improvement across all industries, with the average score rising to 6.5. "In general terms, things show a modest improvement year to year - the overall average score went up just a tad," said Terry Golesworthy, president of The Customer Respect Group.

That's largely because of efforts by companies in the top 25. Many companies at the bottom of the group's rankings did not improve at all - or in some ways got worse. "Thus, the gap between the most and least respectful companies is widening," Golesworthy said.

The highest-rated companies improved in terms of transparency, particularly when it comes to publicly detailing their privacy policies to their online visitors, he said. "We saw a lot of companies in the 'excellent' categories that improved in the area of data privacy, and there was also an increase in the number of companies that have chosen not to share data with outside organisations," Golesworthy said.

Overall, 15 percent of online inquiries sent were ignored, the survey showed. And while 58 percent of all e-mails were responded to within a day, only half of the responses were helpful, according to the survey.

"Customer respect, or lack of, is a significant factor that influences online behavior," Golesworthy said in a statement. "It's no surprise that companies that do more business via the Internet are doing better. Simply put, they get it. No organisation, however, can ignore the online customer, regardless of what percentage of its sales are derived from the Internet."

The Customer Respect Group is hardly whiter than white however. For some reason it follows the irritating habit some organisations have for over-using Javascript on its website, making permanant links to material on its site impossible.