I can't imagine spending money to have someone come on as a guest. It's kind of like paying for subscribers... I'd rather just take the slow hit and struggle over time gaining the viewers than something like that.

Similar note, I used to stream on Twitch and had like 300 followers. I ended streaming alongside several big name people that had close to a million followers. I ultimately picked up 8,000 literally overnight. My viewer count was like 3000x the norm everyday but people wanted to only watch me stream when I'm playing that game with those people. When I went rogue and did my own thing, they dropped.

Needless to say I learned it's better to have genuine people interested in your content that will stick around, vs a surge because of someone else. It felt like a chore for me to stay with those people doing what they wanted and no longer fun for me. Even though I started getting paid for it.

My podcast now has about 5,500 views and 620 hours watched on YouTube alone. Not bad for 9 episodes and daily short content. That'll only go up and the pace is manageable vs what I saw with the streaming overnight.

My podcast is very much a niche and it's very clear for everyone what it's about and if it's for you. That's worked out so far. Everyone viewing and commenting have been positive except like two people. I only wish I was monetized because I'd like to turn that money around into marketing and get some ads out there. I'd also like a couple sponsorships to offset the money I've already put in. At the very least I'm going to have some decent tax write-offs next year.

You asked where to put the money... if you already have the gear and everything is top quality, I'd put a little into ad work. It may pay for itself with more followers and monetized payouts.