Shares of Rackspace gained almost 5% in extended trading after reporting better-than-expected Q3 loss and bullish guidance for the current quarter.The company's Q3 loss before certain costs came in at four cents per share, lower than the anticipated loss of seven cents per share.Rackspace reported total sales of $675.8 million in the quarter, down 8% from a year earlier but slightly ahead of estimates.The cloud services provider is making progress with record bookings growth and aims to return to growth in its public cloud business.