I came across this site while doing a search for examples that I could use to explain why multiple contact channels could be confusing to customers. It turns out that it's easy to find information that explains the importance of multiple contact channels when it's "for customer support, contact us through our toll free number or email or on our Facebook page or Twitter." Unfortunately, finding an explanation for why it's confusing to say "for customer support, contact Bob at this number, Fred at this number, or Carol at this number" turns out to be a difficult search.
Needless to say, in the process, I came across this site, Customer Innovations. There are some great examples of the psychology of customer experience here. Dive in and you'll probably spend a while reading!