I think it must be noted that this is very old - apparently written in 2009 - and while it may have been good at the time, it does not reflect the current state of affairs.
NoSQL has a place, but IMO that place is not primary data storage (in most cases.)
I asked one large, household-name IT company on a recent interview what they'd do if their DC containing all of their Cassandra nodes went down. Their response was "it doesn't go down" (and if it did, they'd lose data)... ... ... amateurs.
Is there any good article about all advantages of nosql and rdbms? Because I think this decision is very hard to make if you have no experience with much data and handling