|
Equity Compensation (Tables)
|
3 Months Ended |
|
Mar. 31, 2015
|
| Equity Compensation |
|
| Summary of stock option activity |
|
|
|
Shares
Subject to
Options
Outstanding
|
|
Weighted
Average
Grant Date
Fair Value
|
|
Weighted
Average
Exercise
Price
|
|
Weighted
Average
Remaining
Contractual
Life (Years)
|
|
|
Balance at December 31, 2014
|
|
4,851,221
|
|
|
|
$
|
10.57
|
|
|
|
|
Granted
|
|
41,000
|
|
$
|
6.87
|
|
13.14
|
|
|
|
|
Exercised
|
|
(96,990
|
)
|
|
|
5.05
|
|
|
|
|
Expired
|
|
(5,074
|
)
|
|
|
11.41
|
|
|
|
|
Forfeited
|
|
(14,081
|
)
|
|
|
12.35
|
|
|
|
|
Balance at March 31, 2015
|
|
4,776,076
|
|
|
|
10.70
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Exercisable options at March 31, 2015
|
|
2,721,289
|
|
|
|
7.49
|
|
5.7
|
|
|
Vested and expected to vest at March 31, 2015
|
|
4,596,162
|
|
|
|
10.50
|
|
6.9
|
|
|
| Summary of stock options outstanding and exercisable |
|
|
|
Options Outstanding
|
|
Options Exercisable
|
|
|
Range of Exercise Prices
|
|
Weighted
Average
Exercise
Price
|
|
Number of
Underlying
Shares
|
|
Weighted-
Average
Remaining
Contractual
Life (in
years)
|
|
Number of
Underlying
Shares
|
|
Weighted-
Average
Remaining
Contractual
Life (in
years)
|
|
|
$0.78 - 1.72
|
|
$
|
1.10
|
|
26,639
|
|
0.5
|
|
26,639
|
|
0.5
|
|
|
1.97 - 3.38
|
|
2.57
|
|
238,762
|
|
1.6
|
|
238,762
|
|
1.6
|
|
|
3.58 - 6.14
|
|
5.66
|
|
1,510,318
|
|
5.4
|
|
1,412,151
|
|
5.4
|
|
|
6.34 - 9.94
|
|
8.29
|
|
981,727
|
|
7.0
|
|
668,671
|
|
6.9
|
|
|
11.28 - 16.97
|
|
13.91
|
|
1,214,668
|
|
8.8
|
|
162,600
|
|
6.2
|
|
|
17.66 - 22.92
|
|
21.00
|
|
803,962
|
|
8.9
|
|
212,466
|
|
8.8
|
|
|
|
|
|
|
4,776,076
|
|
|
|
2,721,289
|
|
|
|
|
| Summary of aggregate intrinsic-value of options exercised, exercisable, and vested and expected to vest |
The following table summarizes the aggregate intrinsic-value of options exercised, exercisable and vested and expected to vest (in thousands):
|
|
|
For the three months ended
and as of March 31, 2015
|
|
|
Options Exercised
|
|
$
|
782
|
|
|
Options Exercisable
|
|
14,232
|
|
|
Options Vested and Expected to Vest
|
|
15,915
|
|
|
| Schedule of assumptions used to estimate fair value of option awards |
|
|
|
Three Months Ended March 31,
|
|
|
|
|
2014
|
|
2015
|
|
|
Expected volatility
|
|
56 – 60
|
%
|
54 – 55
|
%
|
|
Expected dividends
|
|
0
|
%
|
0
|
%
|
|
Expected terms (in years)
|
|
3.8 – 6.1
|
|
6.1
|
|
|
Risk-free rate
|
|
1.1 – 2.0
|
%
|
1.3 – 1.6
|
%
|
|
| Schedule of total stock-based compensation expense classified in statements of operations |
Total stock-based compensation expense has been classified as follows in the accompanying statements of operations (in thousands):
|
|
|
Three Months Ended March 31,
|
|
|
|
|
2014
|
|
2015
|
|
|
Cost of revenue
|
|
$
|
20
|
|
$
|
47
|
|
|
Research and development
|
|
478
|
|
772
|
|
|
Sales and marketing
|
|
222
|
|
454
|
|
|
General and administrative
|
|
527
|
|
576
|
|
|
Total stock-based compensation expense
|
|
$
|
1,247
|
|
$
|
1,849
|
|
|