Stock-based compensation (Tables)

12 Months Ended

Mar. 31, 2013

Fair Value of Options, Black-Scholes Model Assumptions

 The fair value of each option is estimated on the date of grant using the Black-Scholes model with the following assumptions:

	Years ended March 31,
	2011	2012	2013
Dividend yield	0%	0%		—
Expected term	5.5 – 7 years	5.5 – 7 years		—
Risk free interest rates	2.04% – 2.77%	1.23% – 2.84%		—
Expected volatility	75.88% – 77.61%	78.36% – 81.98%		—

Compensation Cost Allocated to Cost of Revenues and Operating Expenses

The compensation cost has been allocated to cost of revenues and operating expenses as follows:

	Year ended March 31,
	2011		2012		2013
	US$		US$		US$
Cost of revenues		78,559		60,224		50,151
Sales and marketing		161,506		138,930		122,316
Product development		187,378		385,737		321,473
General and administrative		131,714		202,983		262,150

Stock Option Plan 2002

Summary of Option Activity

A summary of option activity under the 2002 ESOP plan as of March 31, 2013, and changes during the year then ended is presented below:

Options	Number of Options (in terms of shares)		Weighted average exercise price		Weighted average remaining contractual term (year)		Aggregate intrinsic value
			US$				US$
Outstanding as at April 1, 2012		17,750		16.61
Expired		1,250		2.28
Outstanding as at March 31, 2013		16,500		17.69		5.6		—
Exercisable as at March 31, 2013		8,625		13.70		3.2		—

Stock Option Plan 2004

Summary of Option Activity

A summary of option activity under the 2004 ESOP plan as of March 31, 2013, and changes during the year then ended is presented below:

Options	Number of options (in  terms of shares)		Weighted average exercise price		Weighted average remaining contractual term (year)		Aggregate intrinsic value
			US$				US$
Outstanding as at April 1, 2012		135,487		11.40
Forfeited		375		5.16
Outstanding as at March 31, 2013		135,112		11.41		3.6		19,600
Exercisable as at March 31, 2013		117,237		12.37		3.2		12,450

Stock Option Plan 2006

Summary of Option Activity

A summary of option activity under the 2006 ESOP plan as of March 31, 2013, and changes during the year then ended is presented below:

Options	Number of options (in terms of shares)		Weighted average exercise price		Weighted average remaining contractual term (year)		Aggregate intrinsic  value
			US$				US$
Outstanding as at April 1, 2012		516,438		8.48
Forfeited		10,625		5.26
Outstanding as at March 31, 2013		505,813		8.50		5.9		1,132,420
Exercisable as at March 31, 2013		363,563		9.80		5.3		793,030