A couple of days ago I wrote kinda ecstatic about the possibilities of Maltego. Turns out, I am right [duh!].
Anand Rajaraman is the Consulting Assistant professor at the Computer Science Department at Stanford University, and he drives the point home much better in this article. To sum ot up, if you have limited resources, add more data rather than fine-tuning the weights on your fancy machine-learning algorithm. Of course, you have to be judicious in your choice of the data to add to your data set.
That is exactly what Maltego does and lets you do. It gives a plenitude of data sources and lets you, the human, decide what information weights most, considering your particular query.