Table:
|  |  | Year Ended December 31, |  |  |  |
| --- | --- | --- | --- | --- | --- |
|  | 2019 | 2018 | 2017 | 2018 to 2019 % change | 2017 to 2018 % change |
|  |  |  | (In thousands, except percentages) |  |  |
| Sales and Marketing | $ 396,514 | $ 291,668 | $ 211,918 | 36% | 38% |
Paragraphs:
Sales and Marketing Expenses
Sales and marketing expenses increased $105 million, or 36%, in 2019 compared to 2018. The overall increase was primarily due to increased employee compensation-related costs, including
amortization of capitalized commissions, of $72 million, driven by headcount growth, and an increase in marketing program costs of $8 million. The increase in marketing program costs was driven by increased volume of advertising activities. Further contributing to the overall increase was an increase in allocated shared costs of $14 million.
Sales and marketing expenses increased $80 million, or 38%, in 2018 compared to 2017. The overall increase was primarily due to increased employee compensation-related costs, including amortization of capitalized commissions, of $55 million, driven by headcount growth, and an increase in marketing program costs of $10 million. The increase in marketing program costs was driven by increased volume of advertising activities. Further contributing to the overall increase was an increase in allocated shared costs of $11 million.
Question:
What is the driver for an increase in marketing program costs from 2018 to 2019?
Answer: The increase in marketing program costs was driven by increased volume of advertising activities.