Traffic to Google Checkout has overtaken that to rival online payment service PayPal for the first couple of weeks in December.
Hitwise's Robin Goad finds that the payment service has taken a marginal lead, though this doesn't necessarily indicate that more people are making payments through Google Checkout.
As you would expect, the majority (59.1%) of PayPal's traffic comes from parent company eBay, 12.4% from Google, and just 2.2% from shopping and classified sites.
Google Checkout, by contrast, gets more traffic from retailers, with 45.3% coming from the shopping and classifieds category.
The downstream traffic from both payment providers tells another story - 43.4% visit another shopping and classifieds site after Google Checkout, compared with just 26.7% for PayPal.
This suggests that many more people are abandoning their purchases on Google Checkout than on PayPal.
User numbers for Google Checkout are unavailable, but PayPal recently announced that it had almost 35m user accounts in Europe, where it processed $8.4bn (£4.3bn) in payments last year.