Facebook gamemaker Zynga ploughed onto the stock market with a billion-dollar listing on Friday, one of the largest since Google\'s public offering in 2004. Offering 100 million shares -- one seventh of the company\'s total -- at $10 a pop, the maker of Facebook games FarmVille and Mafia Wars was valued at a whopping $7 billion. Zynga\'s entrance is the largest Internet IPO offering since Google went public in 2004, surpassing online bargain service Groupon, which raised $700 million when it went public last month, only to see its stock price fluctuate wildly. Despite concerns by some analysts that new Internet stars are being precariously overvalued, Zynga\'s stock was snapped up quickly. In the first minutes of trade the shares were selling on the Nasdaq market at around $11 a share, a 10 percent premium. But after a half hour trade the shares were about even, despite the Nasdaq Composite index gaining more than 1.3 percent. Zynga offered only a small portion of the company\'s stock, about 14 percent, to the public. Investors remain hungry for technology stocks and Zynga has shown it can make a profit, according to Virginie Lazes of investment bank Bryan, Garnier & Co. Besides FarmVille, Zynga, which was founded in 2007, makes popular games such as CityVille, Words With Friends and Zynga Poker that run on Facebook and other platforms. Zynga games are free to play but the company makes money by selling virtual in-game goods to players and serving up advertising. The games developer boasts around 230 million players per month in 175 countries, dwarfing its social gaming competitors, and reported cumulative revenue of $1.5 billion in its SEC filing. Zynga said revenue soared nearly five-fold last year over the previous year to $597.4 million and it reported a net profit of $27.89 million. For the first nine months of this year, Zynga reported revenue of $828.9 million, up from $401.7 million during the same period last year, and a net profit of $30.6 million. The San Francisco startup is listed as \"ZNGA\" on the NASDAQ stock exchange. Ahead of the listing Global Equities Research analyst Trip Chowdhry was less bullish on Zynga\'s prospects, saying it was overvalued at $7 billion and that a more realistic figure would be between $2 billion and $2.5 billion. \"The valuation is very ahead of the fundamentals,\" Chowdhry said. \"What you\'re seeing today is its peak,\" he said. \"There\'s only one way it can go and it\'s down.\"