<b>Curiosity-gap subject lines are a tax on yourself</b>

<b>Curiosity-gap subject lines are a tax on yourself</b>

Popular advice: "Write a mysterious subject line so they have to open it."

Myth. Manufactured intrigue — "quick question," "idea for you," "saw this" — gets the open and immediately spends the goodwill, because the body never matches the mystery. The reader feels tricked, and a tricked reader doesn't reply, they delete and remember the sender. A flatly honest subject ("paid collab, $X, one post") filters for people who actually want the deal and pre-sells it. Curiosity buys a worse open than honesty buys a reply.