Licenses - Analyst vs Viewer

Hi,

I have been informed that the SAP BI 4 licenses have been setup as follows:

- Analyst License: User can amend/create reports in SAP BI 4 Suite (WebI, OLAP analysis)

- Viewer License: If the user has a SAP ECC or BW license they can use SAP BI 4 as well for "free" or should i say its included.

Question I have:

- Is there any more information on this anywhere?

- How does this work from a SAP BI 4 license key perspective?

Cheers,

Gurvinder