An online tutoring service should consist of the following components:
Real video and audio. Real video is essential so that visual feedback essential to learning is present and audio for ease of use without additional phone bills and inconvenience of dealing with two separate devices. Online audio is typically based on VOIP which is a mature technology and is being used for real phone services (Skype, Vonage). There are four tiers of online tutoring services - those with real audio and video incorporated in their technology, those using public domain set up such as MSN Messenger with less central coordination, those who implement online tutoring as a keyboard chat room with no audio or video, and those without any online tutoring component.
Tutors are validated or are employees. When tutors are not validated and simply pay the service to operate as tutors, there is no central check to ensure the quality and authenticity of tutoring or ascertain security for the children students.
Affordable. Many online tutoring services are prohibitively expensive.
Should include all components of learning - instructional, demonstrative, collaborative, and individual research. Instructional and demonstrative is by tutors. Collaborative through online discussion or chat group with peers. Individual research includes teaching materials, quizzes, etc. that is available to students separate from the online instructional component.
Should emphasize some level of online security for students and tutors.