Full disclosure first: WeltPixel Conversion Tracking is ours, so weigh that however you like against everything else suggested here.
Two separate things shrink a remarketing audience below your traffic, and at a $3,500 order value the second one is usually the bigger leak.
The first is event loss, and you can size it this morning. Pull last week's Shopify session count and set it next to the pixel's PageView count for the same week, in your store's timezone. That fraction is the ceiling on any website audience you can build. landing around 90%? Your pixel is fine and no tool on earth is finding you much more.
The second is how long a browser stays recognizable, and that one is structural rather than broken. Meta's browser cookie gets written by JavaScript, and Safari caps it at seven days. Nobody decides on a handmade sofa in seven days. So somebody who browsed three weeks ago isn't in your 30-day audience no matter what the pixel does, and a big slice of your pool is effectively rolling seven days. High-ticket retargeting always reads as too small against traffic for exactly this reason.
Our extension fixes the first hole. It does nothing at all for the second, and neither does anything else sold as server-side, because firing events from a server doesn't make an anonymous browser stay recognizable longer than the browser allows. that's the question worth asking before paying anyone, us included.
What actually moves the needle at your price point is targeting that doesn't depend on browser membership: customer list audiences built from every email you've captured, value-based lookalikes seeded on real purchasers rather than viewers, and a longer consideration window handled through email and remarketing lists instead of pixel pools. How much of your traffic is cold and on Safari? If it's a lot, the pool you're staring at may already be close to what that traffic can produce.
