Having 'unlimited' historical data is meaningless in and of itself. You need to know what to do with the data.
Because most people who do that kind of thing fail badly, through overfitting. And they normally fit specific to a market, and they also have to refit their models frequently. So this guy is doing something genuinely different, and making a success of something that most people fail at. Personally I find that interesting. There's also enough of a hint that I can speculate on what they might be doing, compared to say Jim Simons where I have absolutely no clue and I probably couldn't replicate it anyway.
So it's more like Ferrari revealing a concept car with no engine that still runs.
GAT
You can get unlimited amounts of free daily data from www.quandl.com They have a lot of intraday data as well at low cost.
well, quandl offers mostly only EOD data sets for those international markets that it covers. Not sure about US data, just commenting about their non US market data.
By the way - which book is it? Can't seem to recall this guy.
It has never been easier to get a lot of intraday data at low cost. Take a one month subscription to eSignal classic for $45, use qcollector to take the data out and then cancel.