Hello,
When you upgrade to s2Member Pro, your existing configuration will not change and you can continue using PayPal Standard and not upgrade to PayPal Pro:
*PayPal® Pro is NOT Absolutely Required* s2Member is very flexible. It is now possible to integrate Pro Forms without a PayPal® Pro account, whereby the enhanced Form Shortcodes that s2Member provides can be integrated ONLY with PayPal® Express Checkout.
In other words, if you get declined for PayPal® Pro service, you can still use s2Member Pro Forms. Ask PayPal® to activate Express Checkout for you. ( it's free ). Once Express Checkout is enabled, you will have access to your PayPal® API Credentials. Log into your PayPal® account, and navigate to Profile -> API Access (or Request API Credentials). You'll choose ( Request API Signature ).
Now ... here is the tricky part; whenever you generate a Pro Form Shortcode with s2Member, be sure to change accept="paypal,visa,mastercard,amex,discover,maestro,solo" to just accept="paypal"; thereby excluding the on-site credit card processing functionality; which is available only with PayPal® Pro.
However, I think there may be some confusion about how you can use Coupon Codes:
Coupon Codes can only be used with Pro Forms and you cannot create a coupon code for $0.00, the minimum is $0.01:
* s2Member will NEVER allow the Regular Billing Rate ( or Total ) to be less than: $0.01.
If you want to offer something 100% free, please use a Free Registration Form instead.
Either that, or you can offer a Free Trial Period in your Shortcode.
So, after upgrading to s2Member Pro, you could create a Free Registration form using the Pro Forms feature and offer free registration.
Since the s2Member Coupon Code applies the discount
before sending the buyer to PayPal, you must be using a Pro Form to use Coupon Codes (otherwise there is no place to put the coupon code).
If you're using a PayPal Button generated in
WP Admin -> s2Member -> PayPal Buttons, then the buyer goes straight to PayPal and there's nowhere to enter the Coupon Code.
Does that make sense?