|
Note 7 - Stockholders' Equity (Tables)
|
12 Months Ended |
|
Dec. 31, 2014
|
| Note 7 - Stockholders' Equity (Tables) [Line Items] |
|
| Fair Value, Liabilities Measured on Recurring Basis [Table Text Block] |
|
Balance at January 1, 2013
|
|
$
|
2,128,302
|
|
|
Fair value of January 2013 warrants at transaction date
|
|
|
3,305,245
|
|
|
Gain on change in fair value
|
|
|
(1,685,689
|
)
|
|
Balance at December 31, 2013
|
|
|
3,747,858
|
|
|
Gain on change in fair value
|
|
|
(1,549,696
|
)
|
|
Balance at December 31, 2014
|
|
$
|
2,198,162
|
|
|
| Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block] |
|
|
|
Options Outstanding
|
|
|
Options Exercisable (1)
|
|
|
Range of
Exercise Prices
|
|
|
Weighted-average Exercise price per share
|
|
|
Intrinsic
Value(2)
|
|
|
Balance at January 1, 2013
|
|
|
6,432,127
|
|
|
|
|
|
|
$
|
0.88
|
|
|
|
-
|
|
|
$
|
9.64
|
|
|
$
|
1.58
|
|
|
$
|
1,846,040
|
|
|
Exercisable at January 1, 2013
|
|
|
|
|
|
|
2,386,909
|
|
|
|
0.88
|
|
|
|
-
|
|
|
|
9.64
|
|
|
|
2.13
|
|
|
|
205,000
|
|
|
Granted (3)
|
|
|
1,219,500
|
|
|
|
|
|
|
|
1.09
|
|
|
|
-
|
|
|
|
1.75
|
|
|
|
1.43
|
|
|
|
|
|
|
Cancelled or forfeited
|
|
|
(221,402
|
)
|
|
|
|
|
|
|
1.00
|
|
|
|
-
|
|
|
|
9.64
|
|
|
|
4.33
|
|
|
|
|
|
|
Outstanding at December 31, 2013
|
|
|
7,430,225
|
|
|
|
|
|
|
|
0.88
|
|
|
|
-
|
|
|
|
9.64
|
|
|
|
1.47
|
|
|
|
1,493,368
|
|
|
Exercisable at December 31, 2013
|
|
|
|
|
|
|
4,416,292
|
|
|
|
0.88
|
|
|
|
-
|
|
|
|
9.64
|
|
|
|
1.68
|
|
|
|
566,589
|
|
|
Granted (3)
|
|
|
3,284,500
|
|
|
|
|
|
|
|
0.80
|
|
|
|
-
|
|
|
|
1.46
|
|
|
|
1.09
|
|
|
|
|
|
|
Exercised
|
|
|
(162,500
|
)
|
|
|
|
|
|
|
0.88
|
|
|
|
-
|
|
|
|
0.88
|
|
|
|
0.88
|
|
|
|
|
|
|
Cancelled or forfeited
|
|
|
(208,916
|
)
|
|
|
|
|
|
|
0.88
|
|
|
|
-
|
|
|
|
9.64
|
|
|
|
1.42
|
|
|
|
|
|
|
Outstanding at December 31, 2014
|
|
|
10,343,309
|
|
|
|
|
|
|
|
0.80
|
|
|
|
-
|
|
|
|
9.64
|
|
|
|
1.36
|
|
|
|
4,800
|
|
|
Exercisable at December 31, 2014
|
|
|
|
|
|
|
5,627,505
|
|
|
|
1.00
|
|
|
|
-
|
|
|
|
9.64
|
|
|
|
1.56
|
|
|
|
600
|
|
|
| Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block] |
|
|
|
Options Outstanding
|
|
|
Options Exercisable (1)
|
|
|
Range of Exercise Prices
|
|
Number Outstanding
|
|
|
Weighted - Average Remaining Contractual Life
|
|
|
Weighted - Average Exercise
Price
|
|
|
Number Exercisable
|
|
|
Weighted - Average Remaining Contractual Life
|
|
|
Weighted - Average Exercise
Price
|
|
|
$ 0.80
|
-
|
$1.13
|
|
|
5,997,567
|
|
|
|
8.37
|
|
|
$
|
1.05
|
|
|
|
2,055,433
|
|
|
|
6.71
|
|
|
$
|
1.01
|
|
|
1.16
|
-
|
2.13
|
|
|
4,252,117
|
|
|
|
7.37
|
|
|
|
1.70
|
|
|
|
3,478,447
|
|
|
|
6.76
|
|
|
|
1.76
|
|
|
3.20
|
-
|
9.64
|
|
|
93,625
|
|
|
|
3.14
|
|
|
|
6.04
|
|
|
|
93,625
|
|
|
|
3.14
|
|
|
|
6.04
|
|
|
|
|
|
10,343,309
|
|
|
|
7.91
|
|
|
|
1.36
|
|
|
|
5,627,505
|
|
|
|
6.68
|
|
|
|
1.56
|
|
|
| Schedule of Nonvested Share Activity [Table Text Block] |
|
Nonvested Stock Options
|
|
Shares
|
|
|
Weighted - Average Grant Date Fair Value
|
|
|
Nonvested January 1, 2013
|
|
|
4,045,218
|
|
|
$
|
0.56
|
|
|
Granted
|
|
|
1,219,500
|
|
|
|
0.63
|
|
|
Forfeited
|
|
|
(94,833
|
)
|
|
|
0.76
|
|
|
Vested
|
|
|
(2,155,952
|
)
|
|
|
0.58
|
|
|
Nonvested December 31, 2013
|
|
|
3,013,933
|
|
|
|
0.52
|
|
|
Granted
|
|
|
3,284,500
|
|
|
|
0.54
|
|
|
Forfeited
|
|
|
(46,416
|
)
|
|
|
0.58
|
|
|
Vested
|
|
|
(1,536,213
|
)
|
|
|
0.50
|
|
|
Nonvested December 31, 2014
|
|
|
4,715,804
|
|
|
|
0.54
|
|
|
| Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] |
|
|
|
Years Ended December 31,
|
|
|
|
|
2014
|
|
|
2013
|
|
|
Dividend yield
|
|
|
0%
|
|
|
|
0%
|
|
|
Expected Volatility
|
|
|
49.4% to 51.8%
|
|
|
|
43.4% to 46.0%
|
|
|
Risk free Interest rates
|
|
|
1.73% to 2.71%
|
|
|
|
0.92% to 2.10%
|
|
|
Expected lives (in years)
|
|
|
5.5 - 6.0
|
|
|
|
5.0 - 6.0
|
|
|
| Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block] |
|
|
|
Shares
|
|
|
Weighted - Average Exercise Price
|
|
|
Outstanding at January 1, 2013
|
|
|
8,763,836
|
|
|
$
|
0.95
|
|
|
Expired
|
|
|
(41,666
|
)
|
|
|
1.00
|
|
|
Issued
|
|
|
4,643,842
|
|
|
|
1.75
|
|
|
Shares withheld on net settled exercises
|
|
|
(101,318
|
)
|
|
|
0.85
|
|
|
Exercised
|
|
|
(1,127,829
|
)
|
|
|
0.08
|
|
|
Outstanding at December 31, 2013
|
|
|
12,136,865
|
|
|
|
1.33
|
|
|
Issued
|
|
|
8,622,271
|
|
|
|
0.98
|
|
|
Outstanding at December 31, 2014
|
|
|
20,759,136
|
|
|
|
0.91
|
(1)
|
|
| Schedule of Stockholders' Equity Note, Warrants Outstanding [Table Text Block] |
|
|
Exercise
Price
|
|
|
Number Outstanding
|
|
|
Weighted - Average Remaining Contractual Life
|
|
|
Intrinsic
Value (1)
|
|
|
|
$
|
0.60
|
|
|
|
458,977
|
|
|
|
3.14
|
|
|
$
|
105,565
|
|
|
|
|
0.64
|
|
|
|
4,600,842
|
|
|
|
2.16
|
|
|
|
874,160
|
|
|
|
|
0.75
|
|
|
|
2,577,750
|
|
|
|
2.11
|
|
|
|
206,220
|
|
|
|
|
0.86
|
|
|
|
7,432,021
|
|
|
|
4.98
|
|
|
|
-
|
|
|
|
|
0.97
|
|
|
|
343,578
|
|
|
|
2.50
|
|
|
|
-
|
|
|
|
|
1.00
|
|
|
|
1,360,000
|
|
|
|
2.35
|
|
|
|
-
|
|
|
|
|
1.19
|
|
|
|
2,727,274
|
|
|
|
2.50
|
|
|
|
-
|
|
|
|
|
1.75
|
|
|
|
1,233,250
|
|
|
|
4.23
|
|
|
|
-
|
|
|
|
|
8.00
|
|
|
|
25,444
|
|
|
|
0.24
|
|
|
|
-
|
|
|
|
|
|
|
|
|
20,759,136
|
|
|
|
3.37
|
|
|
$
|
1,185,945
|
|
|
| Common Stock Warrants Issued in Private Placement [Member] |
|
| Note 7 - Stockholders' Equity (Tables) [Line Items] |
|
| Assumptions Used in Calculating Fair Value of Warrants Issued [Table Text Block] |
|
|
|
|
|
|
|
|
|
|
|
Transaction Date
|
|
|
|
|
December 31,
|
|
|
January 2013
|
|
|
|
|
2014
|
|
|
2013
|
|
|
Financing
|
|
|
Dividend yield
|
|
|
0%
|
|
|
|
0%
|
|
|
|
0%
|
|
|
Expected volatility
|
|
|
39.3% - 100.0%
|
|
|
|
40.4% - 100.0%
|
|
|
|
47.1% - 100.0%
|
|
|
Risk free interest rates
|
|
|
0.67% - 1.12%
|
|
|
|
1.01% - 1.27%
|
|
|
|
0.91%
|
|
|
Expected remaining term (in years)
|
|
|
2.51 to 3.07
|
|
|
|
3.51 to 4.07
|
|
|
|
5.00
|
|
|