Safe Activation has a free, built-in shopping cart. To process payments, you need a PayPal or Authorize.net merchant account or use ShipIt for free.
Altenatively, a Buy button linked to PayPal, Amazon Simple Pay or Google Wallet can process the order and send data to Safe Activation to fulfill the purchase. Safe Activation is integrated with many external shopping carts.
Setup your products and serial numbers in Safe Activation.
Setup order process to deliver Serial Numbers.
Setup advanced features to fully automate and customize the purchase process.
Create a Buy button for your website for each product you sell.
Decide how you want the shopping cart to interface with your website.
When the setup process is complete, you are ready to sell products.