| Segment reporting | 
|  |  | Three
    Months Ended December 31,
 |  |  
|  |  | 2014 |  |  | 2013 |  |  
| Net revenues |  |  |  |  |  |  |  |  |  
| Marketplace platform |  | $ | 7,597,068 |  |  | $ | 1,392 |  |  
| Services |  |  | 409,984 |  |  |  | 592,066 |  |  
|  |  | $ | 8,007,052 |  |  | $ | 593,458 |  |  
|  |  |  |  |  |  |  |  |  |  
| Gross profit |  |  |  |  |  |  |  |  |  
| Marketplace platform |  | $ | 2,879,923 |  |  | $ | (191 | ) |  
| Services |  |  | 357,033 |  |  |  | 472,320 |  |  
|  |  | $ | 3,236,956 |  |  | $ | 472,129 |  |  
|  |  |  |  |  |  |  |  |  |  
| Operating income (loss) |  |  |  |  |  |  |  |  |  
| Marketplace platform |  | $ | (1,158,430 | ) |  | $ | (667,488 | ) |  
| Services |  |  | 290,541 |  |  |  | 241,846 |  |  
|  |  | $ | (867,889 | ) |  | $ | (425,642 | ) |  
|  |  |  |  |  |  |  |  |  |  
| Depreciation and amortization |  |  |  |  |  |  |  |  |  
| Marketplace platform |  | $ | 164,522 |  |  | $ | 104,710 |  |  
| Services |  |  |  |  |  |  |  |  |  
|  |  | $ | 164,522 |  |  | $ | 104,710 |  |  
|  |  |  |  |  |  |  |  |  |  
| Interest Expenses |  |  |  |  |  |  |  |  |  
| Marketplace platform |  | $ | 4,191,630 |  |  | $ |  |  |  
| Services |  |  |  |  |  |  | 516 |  |  
|  |  | $ | 4,191,630 |  |  | $ | 516 |  |  
|  |  |  |  |  |  |  |  |  |  
| Net income (loss) |  |  |  |  |  |  |  |  |  
| Marketplace platform |  | $ | (5,237,975 | ) |  | $ | (646,152 | ) |  
| Services |  |  | 290,541 |  |  |  | 237,994 |  |  
|  |  | $ | (4,947,434 | ) |  | $ | (408,158 | ) |    
|  |  | As of |  |  | As of |  |  
|  |  | December 31, |  |  | September 30, |  |  
|  |  | 2014 |  |  | 2014 |  |  
| Total Assets |  |  |  |  |  |  |  |  |  
| Marketplace platform |  | $ | 17,677,558 |  |  | $ | 18,118,425 |  |  
| Services |  |  | 202,630 |  |  |  | 171,021 |  |  
|  |  | $ | 17,880,188 |  |  | $ | 18,289,446 |  |  
|  |  |  |  |  |  |  |  |  |  
| Intangible assets |  |  |  |  |  |  |  |  |  
| Marketplace platform |  | $ | 5,607,012 |  |  | $ | 4,234,692 |  |  
| Services |  |  | 5,816 |  |  |  | 6,422 |  |  
|  |  | $ | 5,612,828 |  |  | $ | 4,241,114 |  |    |