San Diego-based ServiceNow has proven that the market for initial public offerings is still strong this morning, opening up at $23.08 in its first day of trading on the NYSE. The firm priced its IPO above estimates, at $18.00 per share, Thursday evening. ServiceNow is now publicly trading as NOW. The firm had earlier estimated an initial pricing range of $15.00 to $17.00. The IPO is a huge win for ServiceNow's venture backers, which include JMI Equity, Sequoia Capital, and Greylock Partners--with JMI Equity's stake in ServiceNow worth over $1 billion, more than an 80x return on its investment. JMI Equity is based in San Diego.