We want to use Google Checkout for our Magento store. Currently, when users clicks checkout button data is sent to Google site and the user can checkout there. We would like to make it do a silent post to Google site, that is we don't want our users to leave our site, it should look like all the processing is in our store.
This is possible in PayPal, but can it be done in Google Checkout too? Are there any examples of implementation?
If not, are there other online payment systems implemented in Magento besides the PayPal which can be used for checkout without leaving the store? I've heard something about AlertPay but I don't know much about it.
When the buyer clicks the Checkout button the shopping cart data is not necessarly sent directly to Google. It can be sent to a web service running on your site and further processed there. The service will use the Checkout API to post the cart to Google. Google will return a URL where your customer can complete the order, and you will redirect the customer to that URL. More info here:
Regarding the final checkout step, the customer has to finish the order through Google - the customer's sensitive information such as login credentials, credit card info, is at Google and thus for security reasons he/she has to leave your website.
If you are selling digital content please have a look at Google In-App Payments. It offers a better in-app (in-site) experience: