From their docs: Note: Please be patient. It may take a long time to train the data model the first time even for very small dataset. It is normal because

From their docs: Note: Please be patient. It may take a long time to train the data model the first time even for very small dataset. It is normal because PredictionIO implements an distributed algorithm by default, which is not optimized for small dataset. You can change that later. Sums up my experience with the Mahout/Hadoop world nicely. Not a good fit for small-medium projects -- too complex, too cumbersome, too slow. By the time you really need the scale (=often never, save for using "Big Data" for marketing), you're big enough and know enough about your domain to roll a custom, efficient, domain-optimized solution. Bringing machine learning to the masses is an honourable goal though, so thumbs up for PredictionIO.