For the nine months ended September 30, 2024, the growth in device revenue from the same period in 2023 is primarily related to an 18% growth in device orders, partially offset by decreased headcount in the sales force and subsequently lower order growth rates, and an increase in distributed products which carry a lower average selling price.
Supplies Revenue
Supplies revenue is related to the sale of supplies, primarily electrodes and batteries, for our electrotherapy products. Supplies revenue increased $2.0 million or 6% to $35.1 million for the three months ended September 30, 2024, from $33.1 million for the same period in 2023.
Supplies revenue increased $7.1 million or 7% to $101.6 million for the nine months ended September 30, 2024, from $94.5 million for the same period in 2023.
The increase in supplies revenue is primarily related to an increased customer base from increased device orders in 2023 and 2024.
Operating Expenses
Cost of Revenue – Devices and Supplies
Cost of revenue – devices and supplies consist primarily of device and supply costs, facilities, operations labor, overhead, shipping, and depreciation. Cost of revenue for the three months ended September 30, 2024 increased $0.6 million or 7% to $10.2 million from $9.6 million from the same period in 2023. As a percentage of revenue, cost of revenue – devices and supplies increased to 20% from 19% for the three months ended September 30, 2024 and 2023, respectively.
Cost of revenue for the nine months ended September 30, 2024 increased $1.4 million or 5% to $29.4 million from $28.1 million for the same period in 2023. As a percentage of revenue, cost of revenue – device and supply decreased to 20% from 21% for the nine months ended September 30, 2024 and 2023.
The increase in cost of revenue – device and supply in the three and nine months ended September 30, 2024 and 2023 is due to the increased volumes related to increased revenue.
Sales and Marketing Expense
Sales and marketing expenses primarily consist of employee-related costs, including commissions and other direct costs associated with these personnel including travel expenses, marketing, and related expenses.
Sales and marketing expense for the three months ended September 30, 2024 decreased $1.4 million or 6% to $20.7 million from $22.1 million for the same period in 2023. The decrease in sales and marketing expense is primarily due to decreased headcount in the sales force, partially offset by increased commissions from increased orders. As a percentage of revenue, sales and marketing expense decreased to 41% from 44% for the three months ended September 30, 2024 and 2023, respectively, primarily due to the items noted above, partially offset by increased revenue.
Sales and marketing expense for the nine months ended September 30, 2024 increased $2.3 million or 4% to $67.3 million from $65.0 million for the same period in 2023. The increase in sales and marketing expense is primarily due to increased commission pay from increased orders, and increased head count in the sales operations department. As a percentage of revenue, sales and marketing expense decreased to 46% from 47% for the nine months ended September 30, 2024 and 2023, respectively. The decrease as a percentage of revenue is primarily due to the increase in revenue during the period.
General and Administrative Expense
General and administrative expenses primarily consist of employee-related costs, and other direct costs associated with these personnel including facilities, travel expenses, professional fees, depreciation, and amortization. General and administrative expense for the three months ended September 30, 2024 increased $2.5 million or 20% to $15.3 million from $12.7 million for the same period in 2023. As a percentage of revenue, general and administrative expense increased to 31% for the three months ended September 30, 2024 from 26% for the same period in 2023.
General and administrative expense for the nine months ended September 30, 2024 increased $7.6 million or 21% to $43.1 million from $35.5 million for the same period in 2023. As a percentage of revenue, general and administrative expense increased to 29% for the nine months ended September 30, 2024 from 26% for the same period in 2023. The increase in general and administrative expense