The answer, in the odd dual role as both matchmaker and spoiler, is Google. It was, after all, Google's phenomenal rise that prodded Microsoft, the dominant technology company for more than two decades, to court Yahoo. And Google's success also weakened Yahoo enough to give Microsoft the sense that it could buy the company at a good price.

Sure, things look rough for Yahoo and Microsoft now that they couldn't agree on a deal. Yahoo's stock has dropped 15 percent, and Microsoft has to figure out another way to catch up in the online ad market, a flaw so big it was willing to pay $47.5 billion to fix it.

In the long run, Yahoo's rejection of Microsoft's acquisition offer could turn out to be brilliant for both companies. Sometimes the best deals are the ones you don't make, especially in technology, where big mergers and acquisitions are notoriously difficult.

Instead of turning into the next AOL Time Warner - a deal regretted enough that the acquirer's name, AOL, eventually was dropped from the corporate title - perhaps Yahoo and Microsoft will be like other companies that were better off after their proposed linkage got scuttled.

Yet it remains to be seen whether Microsoft and Yahoo will fall into this category. If Yahoo management fails to improve the firm's fortunes, or no other suitor emerges, Microsoft and Yahoo still could end up mating after all.

Yes, Yahoo's stock took a beating Monday, but the punishment wasn't as severe as many analysts anticipated because some investors suspect the rivals eventually will renew their mating dance.

Although Microsoft has publicly indicated it will focus on measures besides buying Yahoo in its bid to make its Internet division profitable, several analysts predicted the software maker will revive its bid in the summer or fall if Yahoo can't snap out of a two-year funk that exposed it to an unwanted takeover in the first place.

''Should the frustration of [Yahoo] shareholders come to a boil, we believe [Microsoft] could re-enter the picture, essentially playing the role of the white knight,'' analyst David Hilal of Friedman, Billings, Ramsey & Co. wrote in a research note.

With similar opinions reverberating through the stock market, Yahoo shares shed $4.30, or 15 percent, to close Monday at $24.37. That wiped out nearly half the gain they made since Microsoft made its bid Jan. 31. The drop left the company's market value about $12.5 billion below Microsoft's last offer.

For its part, Google seems poised to benefit no matter how the talks go from here. Unnerved by the prospect of its two biggest rivals joining forces, Google reached out to Yahoo to help thwart Microsoft's bid.

Even if Google doesn't end up selling ads on Yahoo's heavily trafficked Web site, it has kept some of the Internet's biggest services out of Microsoft's clutches.

Google shares gained $13.61, or 2.3 percent, to close at $594.90 Monday.

Microsoft ultimately offered $33 per share for Yahoo, only to be rebuffed. Yahoo co-founders Jerry Yang and David Filo, who still own a combined 9.7 percent of the company's stock, flew to Seattle to demand $37 per share - a price Yahoo's stock hasn't reached in more than two years.

The insistence on a higher price prompted Microsoft CEO Steve Ballmer to yank the offer off the table. Monday's backlash was enough to turn up the heat on Yang and the rest of the Yahoo board. The unrest could lead to a rebellion at Yahoo's still-unscheduled annual meeting, where shareholders could try to oust the board. Yahoo must conduct the meeting by mid-July.

Time Warner Inc. also appears to be in a better negotiating position if it decides to sell its struggling AOL subsidiary, as many analysts anticipate.

Yahoo had been mulling a possible combination with AOL's online operations as a defensive measure against Microsoft. Now, Microsoft may make a run at AOL if its interest in buying Yahoo is truly dead. And if Microsoft enters the picture, Google might offer to increase its 5 percent stake in AOL just to repel Microsoft.

A long list of Internet startups also could be in line for big windfalls if Microsoft and Yahoo step up their efforts to acquire more online weapons to challenge Google. And if Microsoft and Yahoo go shopping, Google has plenty of cash to get into bidding wars for potential takeover targets like Digg Inc., LinkedIn Corp. and Facebook Inc.