Equity Compensation (Tables)
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9 Months Ended |
Sep. 30, 2015 |
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| Equity Compensation |
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| Summary of stock option activity |
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Weighted
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Weighted
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Average
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Shares Subject
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Average
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Weighted
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Remaining
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to Options
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Grant Date
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Average
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Contractual
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Outstanding
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Fair Value
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Exercise Price
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Life (Years)
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Balance at December 31, 2014
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4,851,221
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$
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10.57
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Granted
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212,616
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$
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5.53
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10.95
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Exercised
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(239,726)
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4.82
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Expired
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(13,651)
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12.33
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Forfeited
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(109,170)
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15.37
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Balance at September 30, 2015
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4,701,290
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10.76
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Exercisable options at September 30, 2015
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3,001,261
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8.28
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5.2
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Vested and expected to vest at September 30, 2015
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4,570,238
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10.63
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6.3
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| Summary of stock options outstanding and exercisable |
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Options Outstanding
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Options Exercisable
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Weighted-
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Weighted-
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Weighted
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Average
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Average
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Average
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Number of
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Remaining
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Number of
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Remaining
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Exercise
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Underlying
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Contractual
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Underlying
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Contractual
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Range of Exercise Prices
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Price
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Shares
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Life (in years)
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Shares
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Life (in years)
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$
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1.71
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-
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2.66
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2.47
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211,587
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1.1
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211,587
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1.1
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$
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3.38
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-
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6.14
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5.64
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1,437,561
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4.6
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1,428,774
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4.6
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$
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6.34
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-
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9.94
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8.34
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1,013,900
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6.5
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769,963
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6.0
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$
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11.28
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-
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16.97
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13.71
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1,272,685
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8.3
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279,527
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6.3
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$
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17.66
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-
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22.92
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20.99
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765,557
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8.2
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311,410
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7.8
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4,701,290
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3,001,261
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| 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):
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For the Nine Months Ended
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and as of September 30,
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2014
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2015
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Options Exercised
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$
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17,856
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$
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1,327
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Options Exercisable
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19,883
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5,333
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Options Vested and Expected to Vest
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23,644
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5,389
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| Summary of restricted stock unit activity |
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Number of
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Weighted Average
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Shares
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Grant Date Fair Value
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Non-vested balance at December 31, 2014
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—
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Awarded
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388,000
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$
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8.30
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Vested
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—
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Forfeited
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—
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Non-vested balance at September 30, 2015
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388,000
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| Schedule of assumptions used to estimate fair value of option awards |
The fair value of each option award is estimated on the date of grant using the Black-Scholes option-pricing model with the following assumptions:
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Three Months Ended
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Nine Months Ended
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September 30,
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September 30,
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2014
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2015
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2014
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2015
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Expected volatility
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57
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-
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58
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%
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53
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%
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56
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-
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60
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%
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53
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-
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55
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%
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Expected dividends
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—
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%
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—
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%
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—
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%
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—
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%
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Expected terms (in years)
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6.1
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5.3
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-
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6.1
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3.8
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-
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6.1
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5.3
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-
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6.1
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Risk-free rate
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1.8
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-
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1.9
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%
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1.5
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-
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1.8
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%
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1.1
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-
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2.0
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%
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1.3
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-
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1.8
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%
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| Schedule of total stock-based compensation expense classified in statements of operations |
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Three Months Ended
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Nine Months Ended
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September 30,
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September 30,
|
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|
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2014
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2015
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2014
|
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2015
|
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Cost of revenue
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$
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29
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$
|
40
|
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$
|
77
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$
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126
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Research and development
|
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562
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706
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1,682
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2,145
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Sales and marketing
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296
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|
457
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810
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1,298
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General and administrative
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452
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605
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1,425
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1,767
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Total stock-based compensation expense
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$
|
1,339
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$
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1,808
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$
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3,994
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$
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5,336
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