A counterfeit listing for a trending fashion item does most of its damage in the first days. That is when search interest peaks, when the seller is buying placement, and when your real customers are most likely to land on the fake by accident. Every day the listing stays up in that window costs you sales and seeds bad reviews from buyers who think they bought from you.
The usual delay is evidence gathering. Teams want a perfect filing: test buy completed, photos compared, paperwork lined up. That instinct is understandable and it is also expensive. A good-enough filing on day one beats a perfect filing on day ten, because the listing you are building the perfect case against has already done most of its harm by day ten.
Hour zero is detection: the listing is flagged and triaged. Within the first day, the takedown goes in with the evidence you already have, which is usually your rights documentation plus the listing itself. The test buy runs in parallel, not as a prerequisite. If the first filing gets pushback, the test buy results arrive as the appeal evidence. The point is to get the clock started on the marketplace side as fast as possible.
Fast filings still need to be accurate. Wrong rights holder, wrong listing URL, or a claim that does not match the marketplace's categories will get rejected and cost you more time than the careful version would have. Build templates for your common claims now, so the 48-hour version is fast because it is rehearsed, not because it is rushed.
Quick takedowns only matter if you watch for the re-listing. The same seller will usually try again within days, often with slightly altered titles or new images. Pair every fast takedown with monitoring on the seller account and the product keywords, so the second filing goes in even faster than the first.