Shares of Yelp (NYSE: YELP) the San Francisco-based review Web site, plunged nearly 15 percent Monday, the first day after their $107 million initial public offering.

Yelp shares closed down $3.59 at $20.99, or 14.6 percent below their close on Friday. The decline sliced $215 million off its market capitalization, lowering it to $1.26 billion.

The overall stock market fell slightly, with the S&P 500 down 5.30 to 1,364.33.

Late Thursday, the company priced the shares at $15, or $1 ahead of the prior goal.

The pricing valued the company at $898 million but as a result of the initial activity Friday boosted it to about $1.4 billion.

Yelp sold 7.15 million shares in an offering managed by Goldman Sachs, Citigroup and Jefferies, along with Oppenheimer and Allen & Co.

Yelp's rival, New York-based Zagat, sold itself last September to Google, the No. 1 search engine, for about $225 million in a deal shopped by co-founders Tom and Nina Zagat. They were also the sole co-owners.

Google shares fell $7 to $614.25.

Jeremy Stoppelman, 34, Yelp's CEO, has been preparing the seven-year-old site to be public, having rejected bids from both Yahoo and Google that valued the company at $1 billion. He was VP for engineering at PayPal before its acquisition by eBay.

The CEO didn't sell any shares in the IPO. With 5.91 million shares, his Yelp shares are valued now around $120.4 million, down $20 million from Friday.

Yelp was financed by venture capital, with funds from Elevation Partners, whose investors include Irish rock star Bono; Bessemer Ventures and Benchmark Capital. The trio own nearly 60 percent of the company.

One benchmark in initial Yelp buyers await is profitable operations. The prospectus says Yelp's net loss in 2011 was $16.9 million on revenue of $83.3 million.

The IPO would be among the first of 2012 for an Internet-based commerce site and serve as a lead-in to the Facebook IPO, which seeks at least $5 billion, which might not be ready until the second quarter.

Fourth-quarter IPOs in the sector include shopping site Groupon and gamer Zynga, whose games run on Facebook. Since their respective debuts, shares of Groupon have lost 24 percent and Zynga shares have risen 60 percent. Several others have done better: Jive Software, a business social network specialist, have gained 55 percent, while security software provider Imperva has seen its shares vault 53 percent since its November debut.