I'm currently using Google Checkout as my payment provider but was thinking about adding PayPal too. I'm just curious as to why this "Proceed to secure credit card checkout with PayPal" box appears? It seems to me that this intermediate step is unnecessary. When a customer has made the decision to use PayPal for payment (or a credit card using PayPal's server), doesn't it make sense to take them directly to PayPal to finish the transaction? This is what happens when a customer chooses Google Checkout; they are immediately taken to Google to complete the transaction. I can also understand the confusion that would arise if, after making payment, a customer returns to the same checkout page from whence they came.

I was thinking of adding PayPal as a payment option as an experiment. I'm wondering if one payment processor is more popular than the other. Would I see an increase in sales if I also accepted PayPal? Google Checkout requires customers to create a Google account; this would not be mandatory with PayPal.

With regard to PayPal Pro, I agree with Will that PayPal's fees are a bit much. I already have merchant services through my local bank and process phone and mail order transactions through PC Charge Pro. My fees are much lower than what PayPal wants to charge.

Another point and question regarding PayPal Pro is that it allows customers to complete a transaction on your own web site. That is to say, a customer is not taken to PayPal for payment processing. So, Scott, wouldn't becoming PayPal Pro compliant require SCC to accept data entry from the customer? Would that not require some form of a database for storing customer order information? Lastly, wouldn't that also then require SCC be used on a secure server, which would also require the installation of an SSL Certificate? (Not to mention the need to be PCI compliant, too.)

That secondary step is there so the user knows they are being re-directed to a different location for payment. A good majority of shopping cart applications work in this manner.

Each payment processor serves different user bases. Google Checkout is very big in the US and UK, but not so in other countries. PayPal is pretty much universally accepted. It is more your preference on what you want to offer. Having both just gives your customers the conveniences of using what they are comfortable with or are already registered with.

We will probably never collect any customer credit card information with our software simply because of PCI compliance issues. There are so many laws around this and most people do not understand what responsibilities they should have as a shop owner. For now we will just continue to let the merchants themselves handle all these issues.

Google checkout did offer a slight advantage over PayPal at one time, with a smaller transaction fee structure. Their fees are now identical, so there is no longer any advantage with one over the other. They are both well known, reputable payment gateways and the advantage of having both on your site, is that it gives customers a choice.

Scott is quite right about the legal and security complexities associated with capturing customers credit card details. You need an encrypted database with limited access, vetting and security monitoring of staff that have access to those details, defined security compliance procedures and preferably your own dedicated server to keep hackers away.