Contribute to wikipedia where necessary. Music site uses musicbrainz in a similar way. Birth of open source vocabularies.
Ontology gives us richer more meaningful relationships. Based on common web standards FOAF, Event Ontology etc.
These relationships mean more interesting user journeys, greater link density, and more interesting queries on the data.
But they take more work to populate, a lot more work. Linked data (semantic web) gives us a way of populating our ontology for free.
Using Uberlich we map identifiers and ontology's and we harvests the instances and their relationships from the web.
SWOT
IPTC available as linked data. Strengths. Weakness lack of data in the news event space. Not one CV to rule them all but good enough id’s as vocabulary crosswalks. Getty and DPA.