[Update 2017 May 05 ]
One succinct text on what constitutes good VPN architecture might be found here.
[Update 2015 Mar 30]
An very good article very much in the same direction has appeared on ZDNET.
[Originally published Dec 2013]
Really? How can a terminology hurt me ? Well it can: Indirectly through your wallet. And this is because PaaS/SaaS/IaaS v.s. Cloud nomenclature is not well understood. There is no consistent terminology. Thus people residing on this brave Cloud Computing Planet, do make fundamental mistakes that can cost them a lot. All just because of the initial misunderstandings on the terminology level.