Obviously I skimmed the article far too quickly. Here's the relevant bit:
Compare the numbers of gifts for the two banners:
#18: 832 gifts, $15073.47 total
#22: 301 gifts, $9572.83 total
Not close right? But look at the average gift sizes:
#18: $15.84 for Paypal, $21.87 for credit card
#22: $27.92 for Paypal, $36.58 for credit card
So I was totally wrong in saying that #18 did better overall.