They're not giving it 'for free', they are bundling it into subscription to a bunch of publications that they charge $48 for, and which you then have to remember to cancel before the 'trial' expires. Basically, it's a shill to get you to sign-up for the the book, the chapter, "The High Income Guide", The Financial Intelligence Report (12 month subscription, auto renewing on your card), The Gold Stock Advisor (4 month subscription, auto renewing on your card), The Franklon Prosperity Report (4 month subscription, auto renewing on your card). If they sold only the chapter, I migiht be inclined to do it, but I object to the dishonesty of pretending to 'give you the book+chapter for free', when in fact they'll charge you $48 to get it.
The one at vilcaportal is the old 'unpublished chapter' (from the 1st Aftershock edition - 2009). The latest one (from the 2011 edition) is at http://g-ecx.images-amazon.com/images/G/01/books/wiley/Aftershock_Amazon_Exclusive_Bonus_Chapter(dot)pdf