Quarterly report pursuant to sections 13 or 15(d)

10. Stockholders' Equity (Details 2)

v2.4.0.6
10. Stockholders' Equity (Details 2)
3 Months Ended
Mar. 31, 2013
Mar. 31, 2012
Stockholders Equity Details 2    
Expected life (years) minimum 3 years 6 months 3 years 6 months
Expected life (years) maximum 3 years 9 months 0 years
Expected volatility minimum 46.30% 44.20%
Expected volatility maximum 46.50%  
Weighted-average volatility 46.50% 44.20%
Risk-free interest rate, Minimum 0.36% 0.56%
Risk-free interest rate, Maximum 0.44% 0.60%
Dividend yield 0.00% 0.00%
Expected forfeiture rate 3.90% 2.00%