The average return credit is calculated by dividing the actual shock credits issued by the actual number of trodes returned. A variance in the assumed return rate compared to the actual rate would impact the estimate and potentially understate net sales (overestimated rate) or overstate net sales (underestimated rate) in any given year and create a corresponding misstatement of the liability due to customers.
As of June 30, 2024, the estimated value of our Therapeutic Device customer contract liability was $553. If the expected return rate had increased by 2%, the effect on current year’s reduction in sales and customer liability would have been approximately $61.
Results of Consolidated Operations
Our results of operations for the three and six months ended June 30, 2024 and 2023 are as follows:
Revenue
Revenue for the three months ended June 30, 2024 was $6,131, compared to $6,020 for the three months ended June 30, 2023, an increase of $111, or 2%. Revenue for the six months ended June 30, 2024 was $12,393, compared to $11,502 for the six months ended June 30, 2023, an increase of $891, or 8%.
The increase in sales for the three months ended June 30, 2024 was primarily due to growth of our TRUFORMA® products, including the impact of launching new assays since the comparative period. The increase in sales for the six months ended June 30, 2024 was primarily due to the growth of our existing PulseVet® and TRUFORMA® products, as well as the continued performance of our VetGuardian® products, which had just recently launched during the six months ended June 30, 2023. In general, we expect revenue to increase in subsequent periods as we increase our sales, marketing, and commercialization efforts.
Cost of Revenue
Cost of revenue for the three months ended June 30, 2024 was $1,769, compared to $1,972 for the three months ended June 30, 2023, a decrease of $203, or 10%. Cost of revenue for the six months ended June 30, 2024 was $3,914, compared to $3,619 for the six months ended June 30, 2023, an increase of $295, or 8%.
The decrease in cost of revenue for the three months ended June 30, 2024 was primarily due to non-recurring manufacturing costs incurred during the prior period, as well as lower costs realized from the further integration of our Minnesota manufacturing facility acquired during the second half of 2023. The increase in cost of revenue for the six months ended June 30, 2024 was driven primarily by increased manufacturing expense resulting from higher unit sales. We anticipate that costs of revenue will continue to increase in subsequent periods in line with increased unit sales as described above.
Gross Profit
Gross profit margin for the three months ended June 30, 2024 was 71%, compared to 67% for the three months ended June 30, 2023. Gross profit margin for the six months ended June 30, 2024 was 68%, compared to 69% for the six months ended June 30, 2023.
The increase in gross profit margin percentage for the three months ended June 30, 2024 was primarily due to non-recurring manufacturing costs incurred during the prior period as well as improvements associated with the integration of our Minnesota manufacturing facility. The decrease in profit margin percentage for the six months ended June 30, 2024 was primarily due to the integration of products and new launches, along with product mix impacts associated with the sales of these new offerings.
General and Administrative
General and administrative expense for the three months ended June 30, 2024 was $7,976, compared to $6,850 for the three months ended June 30, 2023, an increase of $1,126, or 16%. General and administrative expense for the six months ended June 30, 2024 was $16,601, compared to $13,863 for the six months ended June 30, 2023, an increase of $2,738, or 20%.
The increase in general and administrative expenses for both comparative periods was driven primarily by proxy and special meeting costs, professional fees for specialized accounting and development work, as well as increased amortization expense associated with acquisitions made in the second half of 2023. These increases were partially offset by lower stock-based compensation expense in both comparative periods. While we expect future general and administrative expense to increase, we anticipate it to decrease proportionally with sales and related product expansion.