| Segment reporting | The following tables summarize segment
information for the three and six months ended March 31, 2016 and 2015:   
    |  |  | Three Months Ended
    March 31, |  |  | Six Months Ended March
    31, |  |  
    |  |  | 2016 |  |  | 2015 |  |  | 2016 |  |  | 2015 |  |  
    | Revenues |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Marketplace platform |  | $ | 1,135,110 |  |  | $ | 3,879,696 |  |  | $ | 4,776,752 |  |  | $ | 11,476,764 |  |  
    | Manufacturing |  |  | 18,448,094 |  |  |  |  |  |  |  | 34,638,124 |  |  |  |  |  |  
    | Services |  |  | 256,719 |  |  |  | 384,283 |  |  |  | 529,481 |  |  |  | 794,267 |  |  
    |  |  | $ | 19,839,923 |  |  | $ | 4,263,979 |  |  | $ | 39,944,357 |  |  | $ | 12,271,031 |  |  
    | Gross profit |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Marketplace platform |  | $ | 255,204 |  |  | $ | 1,579,215 |  |  | $ | 1,850,459 |  |  | $ | 4,459,138 |  |  
    | Manufacturing |  |  | 5,105,793 |  |  |  |  |  |  |  | 9,659,467 |  |  |  |  |  |  
    | Services |  |  | 245,202 |  |  |  | 355,881 |  |  |  | 506,148 |  |  |  | 712,914 |  |  
    |  |  | $ | 5,606,199 |  |  | $ | 1,935,096 |  |  | $ | 12,016,074 |  |  | $ | 5,172,052 |  |  
    | Operating income (loss) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Marketplace platform |  | $ | (1,245,829 | ) |  | $ | (1,381,317 | ) |  | $ | (2,149,574 | ) |  | $ | (2,539,747 | ) |  
    | Manufacturing |  |  | 2,199,635 |  |  |  |  |  |  |  | 3,891,265 |  |  |  |  |  |  
    | Services |  |  | 244,672 |  |  |  | 291,977 |  |  |  | 504,039 |  |  |  | 582,518 |  |  
    |  |  | $ | 1,198,478 |  |  | $ | (1,089,340 | ) |  | $ | 2,245,730 |  |  | $ | (1,957,229 | ) |  
    | Depreciation and amortization |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Marketplace platform |  | $ | 67,967 |  |  | $ | 160,932 |  |  | $ | 136,243 |  |  | $ | 325,454 |  |  
    | Manufacturing |  |  | 447,219 |  |  |  |  |  |  |  | 924,775 |  |  |  |  |  |  
    | Services |  |  |  |  |  |  | 6,693 |  |  |  |  |  |  |  | 6,693 |  |  
    |  |  | $ | 515,186 |  |  | $ | 167,625 |  |  | $ | 1,061,018 |  |  | $ | 332,147 |  |  
    | Interest Expenses |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Marketplace platform |  | $ | 44,066 |  |  | $ | 5,314 |  |  | $ | 110,973 |  |  | $ | 4,196,944 |  |  
    | Manufacturing |  |  | 290,920 |  |  |  |  |  |  |  | 569,496 |  |  |  |  |  |  
    | Services |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    |  |  | $ | 334,986 |  |  | $ | 5,314 |  |  | $ | 680,469 |  |  | $ | 4,196,944 |  |  
    | Provision for income taxes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Marketplace platform |  | $ |  |  |  | $ |  |  |  | $ |  |  |  | $ |  |  |  
    | Manufacturing |  |  |  |  |  |  |  |  |  |  | 413,980 |  |  |  |  |  |  
    | Services |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    |  |  | $ |  |  |  | $ |  |  |  | $ | 413,980 |  |  | $ |  |  |  
    | Net income (loss) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Marketplace platform |  | $ | (935,830 | ) |  | $ | (1,387,197 | ) |  | $ | (1,745,298 | ) |  | $ | (6,625,172 | ) |  
    | Manufacturing |  |  | 1,911,769 |  |  |  |  |  |  |  | 2,772,552 |  |  |  |  |  |  
    | Services |  |  | 242,569 |  |  |  | 291,977 |  |  |  | 491,596 |  |  |  | 582,518 |  |  
    |  |  | $ | 1,218,508 |  |  | $ | (1,095,220 | ) |  | $ | 1,518,850 |  |  | $ | (6,042,654 | ) |    
    |  |  | As of |  |  | As of |  |  
    |  |  | March 31, |  |  | September 30, |  |  
    |  |  | 2016 |  |  | 2015 |  |  
    | Total Assets |  |  |  |  |  |  |  |  |  
    | Marketplace platform |  | $ | 4,152,083 |  |  | $ | 6,811,977 |  |  
    | Manufacturing |  |  | 35,861,555 |  |  |  | 33,714,344 |  |  
    | Services |  |  | 247,714 |  |  |  | 138,035 |  |  
    |  |  |  | 40,261,352 |  |  |  | 40,664,356 |  |  
    | Intangible assets |  |  |  |  |  |  |  |  |  
    | Marketplace platform |  | $ | 1,401,069 |  |  | $ | 1,516,930 |  |  
    | Manufacturing |  |  | 800,000 |  |  |  | 800,000 |  |  
    | Services |  |  |  |  |  |  |  |  |  
    |  |  | $ | 2,201,069 |  |  |  | 2,316,930 |  |    |