When managing client reports with workflows or creating a report database, it may be useful to be able to input information before actually visiting the client. (Spin-off of workflow from "Reporting Each Client Visit Right After Returning to the Office.")
If you are using a workflow system that allows partial input at each task, like Questetra BPM Suite, it's kind of meaningless to separate tasks. Then again, separating tasks would allow sales members to share the progress of their work.
Sometimes a boss or supervisor may request a certain sales staff to go visit a client. So it may be good to allow third-party initiation. (below)