Join our mailing list - experimental behaviour

Wondering how to avoid those annoying popup asking for you to join a new mailing list.

Concept: when the user scroll back to the top of the website a new section is showed. This section contains: clear and short message about the mailing list, a text field, a call to action button.

Let me know what do you think about this idea.
Could it work or it's just non-sense?

Let's discuss.