A buyer who wants your name rarely arrives through your marketing. They type the name into a browser to see if it's taken, the domain resolves, and a page loads. Whatever that page says is your entire pitch. If it's a registrar default, a parking page stuffed with ads, or nothing at all, you just lost the one visitor who was already convinced the name mattered. The for-sale landing page is the storefront on the most valuable traffic you'll ever get: people who found you by typing the exact thing you're selling.
This is a companion discussion topic for the original entry at https://namefi.io/r/en/blog/domain-for-sale-landing-pages