Collaborative Ad Network for Newsletters: Join the Opportunity!

Hi everyone, quick idea I’m exploring and wanted to see if anyone’s interested. I run a finance/investing newsletter (~10k subs, 70–80% open rate), and like many of you, I’ve mostly seen CPC ad offers that don’t really move the needle revenue-wise. I’ve had a handful of conversations with direct sponsors regarding fixed-rate or CPM agreements but I’m usually told to give them a call back when I’m at 100k+ subs. I’m thinking there’s an opportunity here: what if a handful of us (say, 5–10 newsletters with 5k+ subs each) teamed up to form a small vertical ad network? The goal would be to pool our audiences and go after higher-paying, CPM-based sponsorships- the deals that are usually out of reach for solo operators. In an effort to vet this idea, I’ve put together a little Google Form to collect interest from other publishers that are open to giving this a shot. To be clear, I’m not asking for commitments, just gathering a list of interested parties. Happy to chat more or hear feedback if you’ve done anything similar!