How to structure - divide data across subsites or keep in one site with big lists and libraries?

Question

I am planing a new SharePoint 2010 site to store customer information. Each customer can have multiple information associated with them, i.e. tasks, employees, contact information, projects, etc..

It will also be valuable to us to be able to search for information across all customers, and we also need to aggregate customers data together.

My question: Is it better to use a single site where all customers share the same lists and libraries, OR, put each customers information into their own subsite and use the top site to aggregate form the subsite (rollup)?

Being new to SharePoint I am not sure what the pros/cons are for either solution.

Thanks, Egil.

Update: I should add that the site is for internal use only, customers do not have access to the date. All users will have equal access rights over all data.

Answer 1

Maintain a single site collection.For each customer maintain different subsites. Root Site -> Maintain all the components which are common to all customers. Customer Site(Subsite) ->maintain things are pertaining only to that customer(lists/doc library) All Subsites,break the inheritance so that one customer doesnt get to see others information. Develop custom components to query from the root site and show it to customer.this way the data wont be replicated.