Your product launch sequence is your long-format sales letter sent in separated emails (that’s the mental model you should adapt).
I learned this idea from Jeff Walker, the father of online launches, and this still remains a valid idea to date (he uses this since 1996).
Your aim should be to hype your product up to a point where your customers are already sold on the product even if they haven't read the actual sales letter or seen the price.
You can do that by...
Giving hints about what's inside + Let people know what they can accomplish with the information + Give high-value content for free
You should have as many emails as you need to hype it up, often the more the better.
I highly recommend doing a pre-sale where people can buy at a lower price while the product isn't yet released.
When you’re ready to pre-sell your product, have at least 3 or 4 emails dedicated to showcasing why people need your product before the PITCH emails.
When you’re finally ready to launch it, sending up to 3 emails on your launch day is a great strategy to collect a lot of $$$.
People will join the hype, and see how confident you are in your offer.
Don’t worry about it being a lot of emails in a small time-frame.
It is a one-time thing and people will understand and not get mad (even if they do and unsubscribe, they wouldn’t be your buyers anyway).
Product Launch Framework
This is just an example of a framework of an actual sequence, you don’t have to structure yours this way or talk about these subjects.
You can do yours, and there’s no one-way-solution to every industry/niche.
Make sure to save your sequence so you can re-use it if you ever want to run a promotion/relaunch for that product, or simply compare results if you want to re-do it with different content.