NICE just released results of a survey of nearly 1200 adults in US, UK and Australia, focusing on interactions with financial, telecommunications, travel and hospitality, healthcare and insurance services.
The big trend -- no surprise -- is that the Web is the most frequently used interaction channel: 28% of respondents say they interact with their service providers web site at least once per week. But it varies considerable by industry, with financial services customers using the web much more heavily (60% use weekly) and successfully (74%).
However, that boring old phone is still viewed as a more successful channel for accomplishing tasks in telecom, insurance and healthcare.
I must say this matches my experience -- aside from my bank and Amazon.com, most web self-service processes are still too complicated...