Hello,

You could create a product e.g. called Membership with three product options (http://devnet.kentico.com/docs/ecommerceguide/adding_product_option.htm): Gold, Silver and Bronze and sell it as classic products.

If the payment would be alright you would assign the user to appropriate role. You could do it manually after you receive the payment notification (http://devnet.kentico.com/docs/4_0/ecommerceguide/store_settings.htm) or create a schedule task which would for example every day at midnight search the paid orders, find the users according the customer and check his/her roles, eventually it would assign a new role (gold, silver or role) according the order. Please see here: http://devnet.kentico.com/docs/devguide/scheduling_a_custom_code.htm for more information about scheduling a custom code.

The different possibility is to send a password in the Payment result e-mail to the customer. He could type the password in your custom webpart/form control and if it passes it would assign the user to role. Then she/he would need to log out and log in and then he/she would be in appropriate role.
You could develop your own User control (http://devnet.kentico.com/docs/devguide/adding_custom_code_to_the_page.htm) or a Web par (http://devnet.kentico.com/docs/devguide/developing_web_parts.htm) with your custom functionality.

Maybe this article could be helpful for you, too: http://devnet.kentico.com/Knowledge-Base/E-commerce/Direct-PayPal-payment.aspx


Our API Reference is here: http://devnet.kentico.com/downloads/kenticocms_api.zip

Best regards
Ondrej Vasil