AGK has already a lot of support from the current customers/fans. A kick starter campaign could bring more attention to it from who is not, and probably is what TGC needs the most, right?
For that, "selling" AppGameKit focusing on T1 is the best I can think of. BASIC is easy to learn and this is a great appeal to new users that are willing to create games. I understand the C++ is already there "for free" since it is the base of everything, but I really think the Tier 1 is the best AppGameKit could offer.
The campaign should focus mainly in making Tier 1 a professional-grade tool, including awesome IDE, debugging, extensibility, etc...
Also, one thing that Microsoft does very well is their Starter Kits, where you have few very good and complete games that you can change and tweak as you need.
I'm against the subscription model just because implies a monthly commitment and people are usually resistant to that. It could have an additional subscription-based option where you guys can add something else (publishing?).
I think it would be a better model if you sell it once, and create a huge eccosystem where the users can buy assets, sounds, native extensions, etc...
About the later, imagine that you have a basic product, then you offer all Facebook support as an add-on that can be "plugged-in" the Tier 1 (I know Facebook is already there, but is the first thing that came to mind). Same thing about any feature "XYZ" some people are asking for. You could say "I know few people need ScoreLoop support, but not enough to make us do it right now", but if you do it and sell the add-on, you will have a constant revenue stream, right?
All the assets including add-ons could be done by "expert-users" where they get a cut of the sales.
Look at Unity. With the recent change in the licensing for mobile, they are betting on the add-ons/extensions market + a professional version.
You could even add a subscription option for those who choose to where the subscriber could have access to exclusive content like starter-kits, free add-ons, etc.
If you use KickStarter to do this, I'm in
Paulo
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Paulo
http://www.mobilecreators.com