When an online product page contains lots of details, like size charts, fabric explanations, and long customer reviews, page becomes very long. On mobile phones, this means shopper has to scroll down a long way to read everything. If they decide to buy after reading a review at bottom, they have to scroll all way back up to find purchase button. That extra effort can cause users to lose interest.

A sticky add to cart button solves this issue completely. It is a buy button that attaches itself to edge of screen, usually at bottom on mobile phones or top on desktops. As shopper scrolls up and down page to read details, button stays locked in place, remaining visible and clickable at all times.

This minor design change removes friction from shopping experience. No matter where customer is on page, temptation to buy is always just one tap away. It keeps shopping path incredibly simple, which is especially important for mobile users who want quick, effortless interactions while browsing on small screens.