June 27, 2011 - 12:08
All 13 chapters play without any logging in - not sure if this is intentional so get in quick ;)
June 27, 2011 - 13:34
#1
Hi
Good basic introduction.
When you get through past the 13 introductory chapters, and choose one of the two in-depth tutorials you get an introduction and 3 or 4 free (random) chapters, but for anything else you get the payment options page.
So I think its a free-preview strategy.