PALO ALTO — Wilson Sonsini Goodrich & Rosati got a piece of ad tech company Rocket Fuel Inc.’s soaring public market debut last week as an adviser on the offering—and it will also reap rewards as an early investor.

Wilson Sonsini participated in Rocket Fuel’s April 2011 Series C round, which injected $6.6 million of capital and valued the company at $160 million. The $116 million IPO put the company at a valuation nearing $1 billion.