Popups
First-purchase discounts, newsletter signups, campaign announcements — used well they grow your list, used badly they drive people away.

Three things to set
| Setting | Notes |
|---|---|
| Content | Heading, copy, image, button (can be wired to a form) |
| Trigger | After N seconds on site, after scrolling N percent, or on exit intent |
| Frequency | How often one person sees it, and how many days it stays hidden after being dismissed |
Question: Does this hurt SEO?
A popup that covers the full screen the moment someone arrives is treated by Google as an intrusive interstitial and penalized — especially on mobile. Trigger it after "scrolled 50%" or "15 seconds on page" instead, and leave an obvious close button.