Collapsible Content With Password Protection?

Hello!

I am looking for a solution that will allow me to create content for two groups of people in the same post.

So, some of the content will be visible to every reader.

And other content in the same post (perhaps collapsed or otherwise hidden) will require a password to reveal.

My solution right now is to create two separate posts, one with all the content, but password protected, the other with much of the content missing that includes links to the other, password protected, post.

My goal is to increase subscribers to my email newsletter by requiring readers to sign-up to the newsletter in order to receive access to the full content. However, I do not want to require membership or anything like that.

Thanks for any ideas you can throw my way!!

Russ