The fact that people are buying something suggests the traffic itself is fine - that's a decent starting point. If the ad is getting clicks and conversions are happening elsewhere on the site, the problem usually sits between the promise of the ad and the product you're landing them on.
I've seen this play out plenty: the advertised product gets the click, but once someone hits the site they find an alternative that solves the same problem better - better pricing, stronger reviews, or just higher perceived value. In those cases the landing page might not be the culprit, the featured product just isn't the strongest offer in the catalogue.
When users do switch products, are they typically buying a higher-priced item, a lower-priced one, or just a different variation of the same solution? That breakdown tells you whether it's a value perception issue or a positioning problem.
