Do News letter Sponsorships Work For B2B SaaS?

Hello all,

I'm the Founder of https://typestack.ai/

A simple WordPress blog alternative that auto-optimizes your pages for speed & SEO.

I'm looking to connect with someone who tried these paid channels:

1. Betapage / BetaList
2. Swapstack: advertise in newsletters

I'd love to learn from your experience and take your advice on using these channels.

Thanks