Direct Operating Costs
Direct operating costs consist of direct payroll, occupancy costs, data center hosting fees, content acquisition costs, depreciation and amortization, travel, telecommunications, computer services and supplies, realized gain (loss) on forward contracts, foreign currency revaluation gain (loss), and other direct expenses that are incurred in providing services to our clients.
Direct operating costs were $20.5 million and $19.4 million for the six months ended June 30, 2021 and 2020, respectively, an increase of $1.1 million. This increase was primarily due to an increase in direct payroll and payroll related costs of $1.8 million for new hires, stock-based compensation, and bonuses, and a $0.3 million increase in recruitment and professional fees, offset in part by a $0.5 million foreign exchange gain and a $0.5 million decrease in other direct operating expenditures. Direct operating costs as a percentage of total revenues were 62% and 68% for the six months ended June 30, 2021 and 2020, respectively. The decrease in direct operating costs as a percentage of total revenues was primarily attributable to increased revenues in the DDS and Agility segments, offset in part by an increase in direct operating costs.
Direct operating costs for the DDS segment were approximately $15.4 million and $14.4 million for the six months ended June 30, 2021 and 2020, respectively, an increase of $1.0 million. This increase was primarily due to an increase in direct payroll and payroll related costs of $1.7 million for new hires, stock-based compensation, and bonuses, and a $0.3 million increase in recruitment and professional fees, offset by a $0.5 million foreign exchange gain and a $0.5 million reduction in other direct operating expenditures. Direct operating costs for the DDS segment as a percentage of DDS segment revenues were 62% and 71% for the six months ended June 30, 2021 and 2020, respectively. The decrease in direct operating costs as a percentage of segment revenues was primarily attributable to higher revenues, offset in part by an increase in direct operating costs.
Direct operating costs for the Synodex segment were $1.5 million and $1.7 million for the six months ended June 30, 2021 and 2020, respectively, a decrease of $0.2 million. The decrease was principally due to lower software, hardware, and maintenance costs. Direct operating costs for the Synodex segment as a percentage of Synodex segment revenues were 79% and 68% for the six months ended June 30, 2021 and 2020, respectively. The increase in direct operating costs as a percentage of segment revenues during the quarter was primarily due to lower revenues, offset in part by a decrease in direct operating costs.
Direct operating costs for the Agility segment were $3.6 million and $3.3 million for each of the six months ended June 30, 2021 and 2020, an increase of $0.3 million. The increase was due to higher software amortization costs and new hires during the current period. Direct operating costs for the Agility segment as a percentage of Agility segment revenues were 57% and 59% for the six months ended June 30, 2021 and 2020, respectively. The decrease in direct operating costs as a percentage of segment revenues during the quarter was primarily due to higher revenue from subscriptions to our Agility AI-enabled platform and newswire products, offset in part by an increase in direct operating costs.
Selling and Administrative Expenses
Selling and administrative expenses consist of management and administrative salaries, sales and marketing costs including commissions, new services research and related software development, third-party software, advertising and trade conferences, professional fees and consultant costs, and other administrative overhead costs.
Selling and administrative expenses were $12.5 million and $9.1 million for the six months ended June 30, 2021 and 2020, respectively, an increase of $3.4 million. This increase was primarily due to higher payroll and payroll related costs of $2.8 million for new hires, commissions, stock-based compensation, incentives, and bonuses, and increases in marketing related costs and recruitment fees of $0.6 million. Selling and administrative expenses as a percentage of total revenues were 38% and 32% for the six months ended June 30, 2021 and 2020, respectively. The increase in selling and administrative expenses as a percentage of total revenues was primarily attributable to higher expenditures in the DDS and Agility segments, and decreased revenues in the Synodex segment, offset in part by increased revenues in the DDS and Agility segments.
Selling and administrative expenses for the DDS segment were $7.7 million and $5.8 million for the six months ended June 30, 2021 and 2020 respectively, an increase of $1.9 million. This increase was primarily due to higher payroll and payroll related costs of $1.7 million for new hires, commissions, stock-based compensation, and incentives, and increases in marketing related costs of $0.2 million. DDS revenues, DDS selling, and administrative expenses as percentage of DDS revenues were 31% and 29% for the six months ended June 30, 2021 and 2020, respectively. The increase in selling and administrative expenses as a percentage of DDS revenues was primarily attributable to higher expenditures, offset in part by increased in revenues.