You can offer free value on instagram and generate traffic to your homepage where you sell your ebook or offer it for free to generate leads. Your leads (buyers of ebook) should be your ideal customers of your niche. Now you can send them emails with more value and a call-to-action that they contact you. Then sell them your high ticket offer.
I know I probably won't get any replies from this, but I'm gonna start a fitness channel and then after a while, ill use email marketing to sell a fitness course. Which platform is better for going viral and getting views? Tiktok or Instagram?