Zillow's (Z) stock more than tripled after its IPO

Zillow's (Z) stock more than tripled after its IPO Wednesday, then fell back to settle up a 79% at the close.

Zillow tracks home values across the country, offers the data online, and sells ads on its site to make money. It had only $30.4 million in revenue last year and lost $6.7 million. Those numbers are modest, but not modest enough to keep the firm from having a market cap now of almost $950 million, a breathtaking multiple of sales.