Building a sticky sidebar unit that actually sticks

Building a sticky sidebar unit that actually sticks
Sticky rail = best desktop RPM if you build it right:
— Use a 300x600 or 336x280 in the sidebar
— Wrap it: position sticky, top offset ~90px (clear your header)
— Set the sidebar parent to full content height or sticky breaks instantly
— Don't refresh it on scroll — that's a policy gray zone, skip it
— Test on mobile: it MUST collapse to in-content, never stick on small screens
Sticky 300x600 outearns a static one by ~25% for me. The parent-height bug fools everyone.
Steal it.