Building and Maintaining Digital Reference Services. This is an essay by Joann M. Wasik. It was written back when a lot of libraries were first starting digital initatives. I have found that e-mail reference works great. Patrons use e-mail and appreciate this reference assistance. However, chat is problematic. Most patrons don't use chat (it is old technology) but most are now using instant messaging (it is even on their phones!) Maybe that is where digital reference service should concentrate next?
From the site:
Easily accessible digital information has rapidly become one of the hallmarks of the Internet. Online resources have surged in popularity as more individuals and organizations have connected to the global network. Thousands of organizations have turned to Internet-based information delivery as an effective and cost-efficient alternative to traditional communication methods, and many have expanded their services further by interacting with their users and responding to inquiries via the Internet.
Digital reference services (also known as "AskA services," as in "Ask-an-Expert") provide subject expertise and information referral over the Internet to their users. This Digest provides an overview of the growing digital reference movement and its implications on sponsoring organizations, and examines current practices in the creation and maintenance of such services.