When I am informed by the website administrator about a new client purchasing a particular counseling package, I immediately send that client a welcome note.
If I am too busy with clients at hand, we put up an alert about not being available till a specific time period. During that period, if I get an information about a client, I request him/her to wait till I am relatively free to work with him/her. Almost always clients comply and cooperate.
In a welcome note, I request the client to read the terms of service. In this link, the website owner and myself as online therapist, have clarified our terms of service and have explicitly written about our expectations from our clients. We do not work with clients, who tend to provide false information or have illegal motivations or are suicidal.
Those who choose Brief Consultation - I try to send them questions right away to start our work. That saves time and helps client in maximum possible way to address what they have to share and work on. I let them know that this smaller package won't provide us enough chance to complete our therapeutic work. Its like a trial version or a very small snack. One is not fully satisfied. A client therefore might be wishing to have some more and that too in same price.
Those who purchase a bigger package - I send them a questionnaire which is designed to get a preliminary information About the client. In this questionnaire all the items are optional. A client can choose not to reply. I have seen that in general clients do reply sincerely.
We thus end our formal hand-shaking and get down to real business from next session.