Help with First Reader Magnet

So, I just finished listening to Mr. Umstattd’s podcast on reader magnets, and after reflecting on what I learned from it, I need some mentorship.

As you may know, I’m an emerging SFF indie author with a portfolio of eight short stories and a children’s book with a novel currently in the crib. I primarily write a lot of hard sci-fi that breaks tropes, is visionary, and/or has a shock factor element (think classic Twilight Zone or some of Cixin Liu’s works). While my main goal is to constructively challenge established tropes, I am able to work in (a) subtle call(s) to action, provide a reason to hope or experience wonder, or encourage discussion/reflection among readers. I also upload most of these short stories as audiodramas to YouTube.

Alongside my SFF ventures, I give a lot of free worldbuilding advice on YouTube, my blog, and my Substack, based on what I’ve learned along the way when writing my current WIP.

Out of all my content on YouTube that would count as a legitimate reader magnet, the two best-performing videos are a short story twisting the traditional alien invasion narrative (I encourage you to check it out; it’s called The Death of a Species) and a video breaking down why Baron Vladimir Harkonnen from Dune is one of the most well-crafted villains in science fiction. As of this post, they have 63 and 112 views, respectively.

Because of the dual nature of my blog, I am curious if anyone knows how to set up separate channels like those talked about in the podcast, but for Substack so I could include both. If not, do you think that using a short story as a reader magnet for someone who is just starting out is okay to get readers interested in my work? I plan on including a sample of my novel as the reader magnet around the time of release, but I’m not quite ready for that just yet.

Also, do reader magnets just have to be on mailing lists/newsletters, or can they be elsewhere?

Thank you for any help!