Difference between OBIEE and BI Publisher?

If you have OBIEE Suite licence, BI Publisher comes along with the suite as a package. Whereas, you can purchase BI Publisher's licence alone with minimal cost than OBIEE Suite. To consider this, below are the basic differences between two of the Oracle's reporting tools. When your reports are more pixel oriented then BIP is preferable whereas if you are looking more for analytics, graphs, interactive reports, dashboards, etc. then OBIEE is preferable.
Some of more basic differences are as,

OBIEE	OBIEE
For canned and ad-hoc reports	For canned reports only
Fully interactive	Non-interactive unless integrated with OBIEE
Not meant for a real time reporting	Meant for real time reporting
More for trends, analytics, dashboards, etc.	Mainly for fixed format, pixel perfect reports
Drill down is possible	Drill down is not possible
Need DWH/OLAP	OLTP is also preferable

Happy bloggin.. :-)