Spent the last few years watching Amazon/FBA sellers try to jump to their own Shopify store, and it almost always breaks in the same 3 places:

1. They copy the Amazon listing 1:1.

Amazon listings are written for Amazon's algorithm and a buyer who's already comparison-shopping. Shopify buyers land on your page cold — no reviews stacked next to you, no "customers also bought." Your product page has to do all the convincing itself. If you just paste your bullet points over, conversion tanks.

2. They forget they have zero built-in traffic.

Amazon handed you buyers. Shopify hands you a blank store. The sellers who make the jump successfully start driving traffic (email list, retargeting, an audience somewhere) before they migrate — not after. If your plan is "build it and hope," give yourself 3-6 months of runway or don't do it yet.

3. They don't have a customer retention story.

On Amazon, repeat purchases just sort of happen. On Shopify, nothing happens unless you build it — post-purchase email flows, an SMS list, a loyalty angle. Sellers who skip this get a one-time spike from launch day and then flatline.

If you're an FBA seller thinking about this move: the technical setup (theme, apps, payments) is the easy 20%. The traffic and retention plan is the hard 80% — figure that out first.