Obsidian's marketing headline "Sharpen your thinking." is a powerful and concise message. It's especially engaging to potential users who are already familiar with the writing space.

"Sharpen" is the word where this headline really shines. It evokes the image of honing a tool to make it more precise and effective, suggesting that Obsidian can help refine and improve your thought processes where other tools fall short.

By focusing the headline on "thinking" rather than specific features like "notes" or "organization," the headline elevates Obsidian from a mere note-taking tool to something that enhances cognitive capabilities.

Including "your" makes it personal, letting potential users know that Obsidian adapts to their individual thought processes rather than forcing them into a predetermined system.

The brevity of the headline does a great job of reflecting the clarity of thinking it promises. Just as a sharp blade cuts cleanly, this sharp headline delivers its message without any excess words or bloat.

Overall, this headline is effective because it positions Obsidian not just as a productivity tool but as a means of improving how you think. The metaphor of sharpening is thought provoking while keeping the overall message broad enough to appeal to anyone who values clear thinking.