After a rough estimation, it looks like the services hosted on DBTune provide access to 13.1 billion triples, therefore making a significant addition to the data web!

Here is the break-down of such an estimation:

  • MySpace: 250 million people * 50 triples (in average) = 12.5 billion triples ;
  • AudioScrobbler: 1.5 million users (only Europe?) * 400 triples = 600 million ;
  • Jamendo: 1.1 million triples + 5000 links to other data sources ;
  • Magnatune: 322 000 triples + 233 links ;
  • BBC John Peel sessions: 277 000 triples + 2100 links ;
  • Chord URI service: I don't count it, as it is potentially infinite (the RDF descriptions are generated from the chord symbol in the URI).

However, SPARQL end-points are not available for AudioScrobbler and MySpace, as the RDF is generated on-the-fly, from the XML feeds for the earlier, and from scraping for the latter.

Now, I wish linked data could be provided directly by the data sources themselves :-) (Again, all the code used to run the DBTune services is available in the motools project on Sourceforge).