Per Seat Pricing Considerations
When deciding whether to implement an extranet or not (and how you will do it), it is important to estimate usage volume including the expected number of users (not just the number of documents or size of the documents). This will help guide you in estimating the costs of a system implementation.
Per seat pricing, in my view, is rarely a good option within the legal technology field. There are typically a large number of individuals who require access (a seat license) but in reality a small number of people (key administrators, power users, etc.) tend to access the system on behalf of others who are away from the PC, in meetings, or uncomfortable with these technologies.
Some good common sense advice is to be sure to analyze the universe of anticipating clients as you make a decision to get a global product license vs. per seat licenses (which is typically more expensive).