Sent immediately after self-serve signup. Confirms the account, names one next step, opens a reply channel.
Hi {{first_name}},
Welcome to {{ProductName}}.
The fastest path to {{aha_moment}} starts here: {{first_action_link}}.
Estimated time: {{time_estimate}}.
Reply if anything looks broken.
{{Sender name}} One next action and one time estimate. Tells the user what to do without listing every feature. Reply invitation works because founders actually answer in the early days.
Single CTA. A specific time estimate ("takes 90 seconds"). A from-the-founder line for the first 1,000 signups.
A welcome that lists every feature. Multiple CTAs. A generic "thanks for signing up" with no instruction.