4. Loss Per Share

The Company calculates net loss per share in accordance with ASC 260, Earnings Per Share. Under the provisions of ASC 260, basic net loss per share is computed by dividing the net loss for the period by the weighted average number of shares of common stock outstanding for the period. Diluted net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock and dilutive common stock equivalents then outstanding. Common stock equivalents consist of shares of common stock issuable upon the exercise of stock options.

The following table sets forth the computation for basic and diluted loss per share:

	Year Ended December 31,
	2012		2013
Numerator:
Net loss	$	(7,757,079)	$	(8,020,515)
Numerator for basic and diluted earnings per share	$	(7,757,079)	$	(8,020,515)

Denominator:
Denominator for basic and diluted earnings per share — weighted-average shares outstanding		26,742,345		33,481,439

Basic and diluted loss per share	$	(0.29)	$	(0.24)

Outstanding stock options to purchase 1,749,310 and 2,288,076 shares for the years ended December 31, 2012 and 2013, respectively, were excluded from the calculation of diluted loss per share as their effect would have been anti-dilutive.