Millennial Media Inc. (MM) almost doubled in the mobile-ad company’s trading debut, signaling growing investor appetite for companies focused on mobile, social networking, payments and entertainment.

Millennial Media advanced 92 percent to $25 at the close in New York. The company sold 10.2 million shares at $13 apiece in its initial public offering yesterday, after offering them at $9 to $11 each.

Millennial Media, the U.S.’s second-largest mobile-ad company after Google Inc. (GOOG), lets advertisers target consumers through applications on devices such as smartphones and tablets. The Baltimore-based company is in a business that’s attracting growing interest, Eric Jackson, founder of Ironfire Capital LLC, a Naples, Florida-based hedge fund.

“A lot of investors are hungry for returns,” Jackson said in a telephone interview. “Everything that’s seen as a growth company gets a lot of attention.” He doesn’t own any Millennial shares.

Morgan Stanley, Goldman Sachs & Co. and Barclays Plc led the deal, with assistance from Allen & Co. and Stifel Financial Corp. The shares are trading on the New York Stock Exchange under the symbol MM.

To contact the reporter on this story: Olga Kharif in Portland, Oregon, at okharif@bloomberg.net.

To contact the editor responsible for this story: Thomas Giles at tgiles5@bloomberg.net