Two thoughts about this: 1) It seems a little shady to be taking a scrape of another service and putting it up for sale. It may be legal--but shady no less.

Two thoughts about this: 1) It seems a little shady to be taking a scrape of another service and putting it up for sale. It may be legal--but shady no less. 2) More data is not always better. Your application has to be perfectly suited for the data set and if it is not, then you run the risk of drawing false conclusions. Things are not always as easy as they may seem.