What are the advantages of having e-commerce over extranets?    

Extranets are about " joining up" the supply chain-suppliers, resellers, distributors, customers, etc.-enabling business-to business ecommerce and streamlining production and sales process, e.g. By on-line ordering, order tracking and inventory management, and so can dramatically decrease costs in these areas.  Business-to-business sales are expected to outstrip business-to-consumer sales as an Internet growth area.

The benefits and advantages to businesses include:

Less Paperwork- with documents and business processes on an Extranet, information and documents can be accessed, processed, downloaded (and if essential printed out) on demand;