revenue opportunity; income opportunity
A business or economic term for a chance to earn income, often used in discussions of side jobs, investments, or new business models.
A side job creates a new revenue opportunity.
Many income opportunities exist in this market.
収入源 means 'source of income' (a concrete source like a job or investment), while 収入機会 is more about the chance or opportunity to earn income.
Compound of 収入 (income) and 機会 (opportunity). The exact historical derivation is uncertain, but the word follows a common Sino-Japanese compounding pattern.