If the customer enters billing information on the merchant's site, the information can be passed to PayPal (but not Google Checkout) to prepopulate PayPal's forms.
PayPal Website Standard is very simple to use. Simply create a PayPal business account and provide your email. Then create some buttons in PayPal and copy and paste some HTML into your web site. The HTML includes the merchant email address so the button "knows" where to send the money. The merchant never see the customers' credit card information. Links
A seller email address is required to use Website Payments Standard. Please create a seller account within the PayPal Sandbox. Enter the seller email address in the PayPal "Seller Account Email" field in the "Sandbox Testing" section above, then press Update PayPal Info.
Google Checkout offers a variety of options for accepting payment with an easy button generator for Buy Now buttons, or an optional Google Checkout button. Customers are required to create a Google Checkout id and password. The return URL is specified in merchant properties, not an HTML POST, and contact information cannot be prefilled.
Payments are not processed immediately, and instead require manual approval of the merchant. Payments are not immediately available to the merchant and are paid according to Google's payment schedule. The merchant never sees the customer's credit card information. Links
A merchant ID is required to use Google Checkout. Please create a seller account within the Google Sandbox. Enter the merchant ID in the Google Checkout "Merchant ID" field in the "Sandbox Testing" section above, then press Update Google Checkout Info.
PayPal Website Payments Pro accepts credit card and PayPal payments using the two API (reference) solutions Direct Payments and Express Checkout, respectively, which requires a monthly fee. Sites that use Direct Payments must also offer Express Checkout. API credentials, needing a multi-day approval of PayPal, are required.
When using a credit card the customer stays on the merchant web site. Confirmation messages are controlled by the merchant, who can see the customer's credit card information. Links
API credentials are required to use PayPal Website Payments Pro. Please obtain API credentials within the PayPal Sandbox. Enter the API email, password, and signature in the "Sandbox Testing" section above, then press Update PayPal Info.
