The BBC reports that Google's Checkout payment service is now available to UK businesses.
Of end-to-end payments services - those which try to smooth the process of shopping online by storing payment information centrally - Paypal led the pack, with about 25% of the US online payments market.
Other players such as Billmelater took about 5-6% and Google Checkout was on 2%.
But Ed Kountz pointed out that if eBay transactions were taken out of the picture, the non-eBay share for Paypal drops to an estimated 8%-9% - still a comfortable lead, but less overwhelming.
"Checkout's history to date has been a bit like Paypal's evolution on steroids," he said.