Table:
|  | Years ended December 31, |  |  |  |
| --- | --- | --- | --- | --- |
|  | 2019 | 2018 | $ Difference | % Difference |
| Products and licensing costs | $16,684,172 | $8,078,870 | $8,605,302 | 106.5% |
| Technology development costs | 18,649,161 | 15,400,475 | 3,248,686 | 21.1% |
| Total costs of revenues | $35,333,333 | $23,479,345 | $11,853,988 | 50.5% |
Paragraphs:
Cost of Revenues
Our Products and Licensing segment costs increased $8.6 million to $16.7 million for the year ended December 31, 2019 compared to $8.1 million for the year ended December 31, 2018. This increase primarily resulted from $3.9 million of cost of revenues from the legacy business of MOI and $4.4 million of cost of revenues from the legacy business of GP during the year ended December 31, 2019, as well as an increase in sales volume.
Our Technology Development segment costs increased $3.2 million, to $18.6 million for the year ended December 31, 2019 compared to $15.4 million for the year ended December 31, 2018. The overall increase in Technology Development segment costs was driven by increases in direct labor and subcontractor costs consistent with the rate of growth in Technology Development segment revenues.
Question:
What led to the increase in Technology Development segment costs?
Answer: increases in direct labor and subcontractor costs consistent with the rate of growth in Technology Development segment revenues.