These are the payment processors we currently integrate with:
The typical flow goes like this:
The buyer clicks your Add to Cart button(s) to add some item(s) to their cart. The cart will offer a separate checkout button for each payment method you accept -- e.g., if you accept payments via PayPal, Google Checkout, and direct card payments using Authorize.Net, then your cart would show three checkout buttons for buyers to choose. The PayPal checkout button would take the buyer to paypal.com to make payment, the Google Checkout button would take them to checkout.google.com, and the Authorize.Net would bring up a generic card-checkout page hosted by E-junkie.
After the buyer finishes checkout and the payment processor confirms the buyer's payment was good and completed, we grant the buyer access to a thank-you page. If you are selling downloads, this is where we present the buyer's unique download link(s) automatically, and we would also issue them a thank-you email with a link to reach the thank-you/download page in case they did not proceed to the download page after checkout. Their download link(s) expire after the number of attempts or hours (whichever comes first) that you specify in each product's settings.
After receiving the confirmation of completed payment, we also send you a Sale Notification email summarizing who bought what to be shipped where (if relevant), and we log the order data in your Transaction Log; if you have specified an Integration URL, we would POST the order data to there as well for your own post-processing needs.