What are the best marketing channels for conversion optimization?

Channels that allow detailed tracking and testing tend to work best, like paid search, email marketing, and social ads. These give control over audience targeting and landing page variations. Email is especially useful because it reaches a warm audience and supports direct experimentation with content and timing. Paid search lets you match intent with messaging and measure performance by keyword. Organic search and content marketing support CRO, too, more so when paired with intent-focused landing pages.