Give interested people a reason to return. Here are some free ideas for engaging content, ask a youtuber to feature your platform for free access, ask the community if they desire API integrations with other platforms, build a slack/telegram/discord group, etc. In growth hacking, you should focus on returning customers, the low hanging fruit. Therefore, I would focus on the onboarding flow. Where in the funnel can conversion be optimized? For example, you could experiment with Notifia https://notifia.io/, to increase sales. Most people are more likely to subscribe if they see other doing it at the same time. In my opinion, when the hype train has passed, updates won't be enough when the platform has launched. Like if your marketing budget dries up, customers should have reason to return to your platform. I wish you good luck. You have succeeded in giving a good first impression. Now it is time to make every customer your friend. Focus on storytelling, community building, and audience interaction.