Slow mobile load times
Uncompressed images and stacked apps push mobile load past the point where shoppers wait. Speed work is usually the cheapest conversion improvement available.
Product pages that only describe
A spec list is not persuasion. Strong product pages answer objections, show scale and use, and make delivery, returns, and sizing obvious before the shopper has to hunt.
Confusing navigation
If a visitor cannot reach the right collection in two clicks, the catalogue is working against you. Structure collections around how customers shop, not how you file inventory.
No retention flow
Stores without abandoned cart and post-purchase emails leave revenue on the table every single week. These flows are set up once and keep working.