12. Net loss per share attributable to common stockholders

The following table sets forth the computation of basic and diluted net loss per share attributable to common stockholders:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2018			2017			2018			2017
	(in thousands)
Numerator:
Net loss attributable to common stockholders, basic and diluted	$	(522	)	$	(3,450	)	$	(1,636	)	$	(18,347	)
Denominator:
Weighted average common stock, basic and diluted	42,377			40,336			41,890			39,468
Net loss per share attributable to common stockholders:
Basic and diluted	$	(0.01	)	$	(0.09	)	$	(0.04	)	$	(0.46	)

(3) As noted above, prior period amounts have not been adjusted upon adoption of ASC 606 under the modified retrospective method.

For the three and nine months ended September 30, 2018 and 2017, we excluded all assumed exercises of stock options and the assumed issuance of common stock under RSUs from the computation of diluted net loss per share as the effect would be anti-dilutive due to the net loss for the period.

On April 1, 2013, the Company approved a stock repurchase program to repurchase up to $10,000 of the Company’s common stock in the open market, exclusive of any commissions, markups or expenses. The stock repurchased will be retired and will resume the status of authorized but unissued shares of common stock. The Company did not repurchase any of our common stock during the three and nine months ended September 30, 2018. As of September 30, 2018, the remaining approved amount for repurchases was approximately $5,180.