Once you experience the dynamic nature of exploring a graph database with the ability to query things such as “locate all executives interested in graph database technology who live in New Mexico and play racquetball,” it’s hard to return to the rigid world of relational databases.
Relational databases store data in tables and the relationships must be pre-defined before they can be queried. You must foresee ahead of time exactly how you plan to use the data. Relational databases are not conducive to experimenting with data in today’s diverse, untamed, unpredictable data environment. Relational databases are for reporting, not exploring.