Most Shopify stores do not have a traffic problem. They have a product page that fails to answer four questions: what is this, can I trust it, is it worth the price, and do I care about this brand. Shopify conversion rate optimization is the work of finding which question is unanswered and fixing it in the order that pays.
The process runs in six steps: instrument the funnel before optimizing, find the leaking step rather than the loudest opinion, score the page against Clarity, Confidence, Cost, and Cult, ship the highest impact-over-effort fix first, give the change enough traffic to read, and judge everything on mobile where most Shopify traffic lives.
A weak add-to-cart rate is a product page problem. Strong add-to-cart with weak checkout is a cost, shipping, or trust problem. Strong first purchase with a flat repeat rate is a retention problem. Each one has a different fix.