In general, there is limited mixing of salesforce Editions.
You cannot mix GE, PE, EE, or Performance Edition:
However, once you move to Enterprise or Performance edition, there is the opportunity to have some users at those levels, and some users on a "platform" license, which gives them no access to leads, campaigns, oppties, cases, products, and other "CRM" data, but they still have access to accounts, contacts, activities, and custom objects (and report and dashboards of course).
Salesforce helps businesses of all sizes accelerate sales, automate tasks and make smarter decisions so you can grow your business faster. Salesforce CRM offers:
- Lead & Contact Management
- Sales Opportunity Management
- Workflow Rules & Automation
- Customizable Reports & Dashboards
- Mobile Application