The making of into a publicly traded bonanza worth $1.2 billion had going for it what most Silicon Valley companies have — backing from a plugged-in technology angel, experienced Internet and communications executives and even a general counsel poached from a leading tech-law firm.

Handling the initial public offering last March for the company, whose shares this week were trading as high as $83, was a boon to San Francisco’s Brobeck, Phleger & Harrison.