Paypal versus credit card sales: how do people pay?

The chart below shows what percentage of sales at Magnatune come in from credit card payments, versus paypal payments.

Some notes on this data:

* Paypal is responsible for 28% of sales, credit cards are 72%

* the percentages do vary +/- 10%, which is more variation than I would have expected

* In the past 2 months, credit card sales have increased almost 15%. I am not sure if this is due to our selling compact discs now (and thus drawing a less internet-insider crowd) or if this is due to christmas purchasing.

* Paypal tells me that in a typical business they see 10% of sales going to paypal. They don't understand either, why Magnatune's Paypal percentage is almost 3X the norm. I suspect it's because music downloading is a more cutting edge type of e-commerce, and thus tends to attract a more internet-insider (and thus paypal-savvy) audience.