The Alliance of Genetic Support Groups presents

Has this to say about online support groups:

Information and Support:  It more easily permits patients and families to POOL their experiences and practical information, coping skills, discoveries, and evaluations of services/resources. It's much easier and more convenient to attend meetings of an online group.

• Other Positive Aspects:

Online networks promote a much greater consumer role shift from passive patient to pro-active self-helper than face-to-face groups. The availability of comprehensive databases, self-publishing and networking capabilities, and consumer-run mailing lists, forums, and web sites enable and foster a much wider range of self-care, mutual aid, and self-advocacy responsibilities and high-level partnerships with health professionals.

Physicians and other health professionals are more easily available as guest speakers and consultants to self-help groups online. A number of groups have recruited professionals who have made themselves available.

Online networks help members overcome physical barriers. Online networks bypass many traditional barriers to participation, e.g., the lack of a local support group, lack of transportation, time conflicts, or 24-hour-a-day caregiver responsibilities. And with adaptive input/output equipment, even the seriously disabled can more readily participate online.

Online anonymity allows many self-help group members to be more comfortable in sharing sensitive or potentially embarrassing information.

Schwablearning.org says this about online support groups:

The advantage of online support for many is that you can participate in bulletin boards or send emails any time you like. If you're feeling a little shy, you can read what others are saying without having to participate yourself. And if you're having trouble sleeping because you're worrying about your child, you can go online at any hour for information and support.