No 'I' in Google

Similarly, skepticism abounds about Internet phone service, also known as VoIP. Wall Street analysts have long questioned the $2.6 billion that eBay paid for Skype last year. Others wonder about the appeal of click-to-call services.

"The whole purpose of online storefronts was to be 24/7 without a human body," says Andy Abramson of the blog VoIP Watch, in an interview. He adds that click-to-call won't be useful to customers if a merchant isn't around to receive a voice mail.

Google and eBay executives both say that they are pleased with the deal.

"We think that click-to-call is a great way to monetize Skype," says Alex Kazim, Skype's president.

The alliance between Google and eBay, which also includes text-based advertising outside the U.S., came as a surprise. Media reports, which the companies have downplayed, have focused on the growing rivalry between the two, particularly in the areas of online payments.

Plus, eBay signed a similar partnership with Yahoo!(GOOG Quote) for its U.S.-based auctions in May.

"If anything, I think Google having international is a better deal than Yahoo! having the U.S.," because the growth rates are better, says Pyykkonen.