Kit (formerly ConvertKit) is an email marketing platform for creators who sell things: tagging, sequences, commerce, automations that actually branch. Beehiiv is a publishing platform for creators who write things: fast editor, growth loops, ad monetization.

If your revenue comes from launches and products, Kit's automation depth wins and it is worth the extra setup. If your revenue comes from the newsletter itself — sponsors, subscriptions, referrals — beehiiv gets you there with less work.