Physical units purchased in the quarter and six months were lower 14.3% and 22.7%, respectively, due to the quality of content released compared to the same prior year periods. Further, during the three and six months ended June 30, 2022, the Company experienced persistent periods of time with no new releases driving inconsistency in customer rental patterns and continue to remain below 2019 (pre-COVID) levels. The Company expects studios to return to a more normal release slate with new release content building throughout 2022 as the pandemic subsides.
Partially offsetting the decline in revenue for the Legacy Business, the Company’s kiosk servicing business experienced solid growth during both the three and six months ended June 30, 2022. The Company experienced modest growth in rental revenue per physical rental during the three and six months ended June 30, 2022. Further, the Company’s Digital Business experienced strong double-digit growth across all of the Company’s digital offerings during the three and six months ended June 30, 2022.
Product Cost. Product Cost for the three months ended June 30, 2022 was $28.8 million, an increase of $0.1 million or 0.3%, compared to $28.7 million for the same period in 2021 reflecting increased costs of digital content, partially offset by variable cost savings.
Product Cost for the six months ended June 30, 2022 was $56.0 million, a decrease of $0.9 million or 1.5%, compared to $56.9 million for the same period in 2021 due to variable cost savings, partially offset by increased costs for digital content.
Gross Margin. Gross margin for the three months ended June 30, 2022 was $37.2 million, a decrease of $3.5 million or 8.5%, compared to gross margin of $40.7 million for the three months ended June 30, 2021 due primarily to lower net revenue as discussed above.
Gross margin for the six months ended June 30, 2022 was $73.2 million, a decrease of $16.0 million or 18.0%, compared to gross margin of $89.2 million for the six months ended June 30, 2021 due primarily to lower net revenue as discussed above.
Gross margin as a percentage of net revenue decreased to 56.4% for the three months ended June 30, 2022 as compared to 58.7% for the same period in 2021, reflecting increased upfront costs for certain theatrical titles coupled with lower net revenue.
Gross margin as a percentage of net revenue decreased to 56.6% for the six months ended June 30, 2022 as compared to 61.0% for the same period in 2021, reflecting increased upfront costs for certain theatrical titles coupled with lower net revenue.
Direct Operating Expenses. Direct Operating expenses were $31.4 million for the three months ended June 30, 2022, a decrease of $0.1 million or 0.3%, compared to the same period in 2021 reflecting lower variable costs including retailer revenue share expenses, partially offset by increased costs in connection with the optimization of the Company’s kiosk network.
Direct Operating expenses were $61.4 million for the six months ended June 30, 2022, a decrease of $3.1 million or 4.8%, compared to the same period in 2021 due to lower variable expenses including credit cards fees and retailer revenue share expenses, partially offset by costs incurred in connection with the optimization of the Company’s kiosk network.
Marketing Expenses. Marketing expenses decreased by 12.8% to $3.1 million for the three months ended June 30, 2022 as compared to $3.6 million for the same period in 2021.
Marketing expenses increased by 4.1% to $7.1 million for the six months ended June 30, 2022 as compared to $6.8 million for the same period in 2021 reflecting increased investments in the Company’s Digital Business.
Stock-Based Compensation Expense. Stock-based compensation expense was $2.0 million and $0.2 million for the three and six months ended June 30, 2022, respectively, compared to $3.8 million and $0.7 million for the three and six months ended June 30, 2021, respectively, primarily due to the equity award granted in connection with the Redbox Equity Plan.
General and Administrative Expenses. General and administrative expenses for the three months ended June 30, 2022 were $25.7 million, an increase of $9.2 million or 56.0%, compared to $16.5 million for the same period in 2021. The $9.2 million increase includes $10.7 million in legal and advisory expenses incurred as the Company explores strategic alternatives, as well as public company costs, which did not occur in the prior year period, partially offset by lower payroll and related costs.
General and administrative expenses for the six months ended June 30, 2022 were $48.9 million, an increase of $19.1 million or 64.2%, compared to $29.8 million for the same period in 2021. The $19.1 million increase includes $14.0 million in legal and