Match the message to the audience
The page should continue the expectation created by the traffic source and promotional message. Large shifts in topic or promise create friction.
Give the page one primary job
For list building, that job may be an email opt in. For another funnel it may be a product page visit or application. Keep competing actions under control.
Make the value understandable quickly
State what the visitor gets, who it is for and what happens after the action. Avoid vague promises that make the visitor work to understand the offer.
Test the mechanics
Check mobile layout, page speed, form submission, redirects, analytics and email follow up before buying traffic.
Measure the right event
A page view is not the same as a lead. Configure measurement around the action that represents real progress in your funnel.