Since Apple’s tracking changes, Meta and TikTok can no longer see most of what happens after someone clicks an ad which means campaigns optimizing purely on pixel data are increasingly bidding blind. The fix isn’t a Shopify checkbox setting; it requires server-side event tracking through the Conversions API, matched carefully against pixel events to avoid duplicate or conflicting signals reaching the ad platform. Creative testing has to move faster to compensate for this loss of precision running more variants means the algorithm has more signal to work with even when individual user-level tracking is limited, which is why the pace of new creative matters as much as the concept itself. Where the ad sends traffic matters just as much as the ad itself: a scroll-stopping TikTok hook that lands on a slow, cluttered product page bleeds spend fast, so paid social performance is tightly coupled to on-site conversion rate testing creative without fixing the landing experience just finds the ceiling faster. At higher spend levels, checkout customization, multi-currency support, and B2B wholesale flows available on Shopify Plus also start to matter, since paid traffic exposes friction points a smaller store wouldn’t hit at lower volume.