Cost of Revenues and Gross Profit
Cost of revenues for the year ended December 31, 2021 was $40.1 million compared to $17.1 million for the year ended December 31, 2020. The 135% increase in cost of revenue for the year ended December 31, 2021 over for the year ended December 31, 2020 grew proportionately with the increase in revenue during the same comparable periods, as well as slight increase in raw material costs.
Our gross profits for the year ended December 31, 2021 increased by $16.4 million, or 134%, as compared to the year ended December 31, 2020. Gross margins of 42% remained flat year-over-year.
Sales Commission
Sales commissions for the year ended December 31, 2021 increased by $14.7 million, or 141%, compared to the year ended December 31, 2020. The increase in sales commissions expenses is primarily attributable to a corresponding increase of 134% in service revenue.
Sales and Marketing
Sales and marketing expense for the year ended December 31, 2021 increased by $2.0 million, or 63%, compared to the year ended December 31, 2020. The increase was primarily attributable to an increase of $1.4 million in personnel-related expenses as a result of increased headcount in our sales and marketing organization, $0.2 million increase in office supplies, and $0.1 million increase in due and subscription expense.
General and Administrative
General and administrative expense for the year ended December 31, 2021 increased by $2.0 million, or 52%, compared to the year ended December 31, 2020. The increase was primarily attributable to an increase of $0.5 million in accounting, legal, and other contract labor costs, $0.3 million in personnel-related expenses, as a result of increased headcount, $0.2 million increase in office and occupancy related costs, $0.2 million increase in customer support, $0.2 million increase in amortization of internal software, a $0.1 million increase in stock-based compensation expense related to additional stock-based awards granted in fiscal year 2022, and a $0.1 million increase in recruitment and reallocation expenses.
Interest Expense
Interest expense for the year ended December 31, 2021 increased by $1.2 million, or 227%, compared to the year ended December 31, 2020. The increase is attributable to a $0.6 million increase in interest expense related to amortization of debt discount primarily due to the 2020-A and 2021-A notes, a $0.3 million increase in interest expense related to our SVB operating loan, and a $0.3 million increase in financing costs associated with a 2021 short-term bridge loan.
Other Income (Expense), Net
Other income (expense), net for the year ended December 31, 2021 increased by $0.2 million, or 485%, compared to the year ended December 31, 2020. The increase was primarily due to increase of $1.3 million related to the fair value measurement of the SAFEs, $0.3 million related to revaluation of derivative liabilities of 2019-A 2020-A and 2021-A notes, and $0.3 million related to fair value remeasurement of Series B and Series C preferred stock warrants. These expenses were partially offset by other income relating to PPP loan forgiveness of approximately $1.7 million.
Net Loss
As a result of the factors discussed above, our net loss for the year ended December 31, 2021 was $9.3 million, an increase of $3.6 million, or 63%, as compared to $5.7 million for the year ended December 31, 2020.
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