Hello all, just joined here and a new user to Terragen.
As a new user to Terragen, and terrain modeling in general, I feel a little left out. While I'm sure each of the above comments are valid, I think one advantage other software packages have is documentation, making the learning curve astronomically faster and therefore increasing adoption.
My thought is, if you can provide the tools to make new users feel comfortable and welcome, you'll convert them to long-term customers overnight. To do so, please consider addressing these ideas:
1. Documentation/Tutorial Videos - Community sourced or other [Grasshopper3D is a good example of official and user generated all mixed together
http://www.grasshopper3d.com/page/tutorials-1]
2. User interface 'Cheat-Sheet'