[TYPO3-shop] Sell software licences

[Gabriel Engel]

Hi,

I am starting a new website and thinking about using the tt_products plug in 
as my e-commerce system.
I want to use Paypal, and on the manual it says:

  sponsors only: Payment gateways with Payment Library extension - Paypal 
and Transaction Central

How do I become a sponsor? How much does it costs?
My website is going to sell software licences, so it is not REAL products 
and they need some special features, like sending the specific LICENCE KEY 
by email, etc.
Do you have any experience with this, or know someone that has used 
tt_products in a similar situation?

Thanks for you time,

Gabriel Engel