Please tell me this is not something you've actually been asked to sign up for 🙈️
But yeah people are unbelievable sometimes... they want to sell a service, more like I'd be the one doing them a service by purchasing whatever-their-thing is.
I've learned to see all newsletter sign-up prompts/"get-a-thing-free" in exchange for signing up to a newsletter/and similar things as icky. In very rare instances I see it as not icky in any way. That's something I'm kind of afraid of as a content creator... the most I would feel comfortable with doing would be asking people to sign up for a (hypothetical) newsletter, but by asking directly. I would feel weird about being like "here, have this free PDF with a bunch of insights (and of course you will be forced onto my newsletter, but that's in small print). Even worse about constantly asking people to buy stuff by way of weekly emails. 🤷♀️️
Eeeeh, sorry for the word vomit, Michelle, just very opinionated about this stuff, haha.