Sort by urgency, not by platform
A buyer asking “is this still available” needs an answer in minutes if you want the sale. A case update on eBay needs an answer before a formal deadline, or the decision can go against you by default. A casual Depop DM can usually wait an hour. None of that urgency has anything to do with which app happens to be open on your phone — which means checking apps in rotation is close to the worst possible sorting method, even though it's the most common one.
Keep buyer and item context next to the message
A huge amount of reply time gets lost just remembering what a conversation is even about — flipping back to a listing to check the price, the condition, or what you already told this buyer last week. Whatever system you use, keeping that context attached to the conversation itself, not buried in a separate tab, is the difference between a ten-second reply and a two-minute one.
Don't answer from scratch every time
The same handful of questions — sizing, bundling, shipping time, “would you take less” — show up constantly across every platform. Typing a fresh answer each time is where most of the wasted time actually lives. A drafted starting point you edit and send is almost always faster than a blank box, even when you end up rewriting half of it.
How Closetline handles all three
This is exactly what Closetline is built around: one queue across every marketplace you sell on, sorted by urgency and overdue time rather than by app; buyer rating, order history, and item photo attached to every open thread; and an AI-drafted reply waiting on each message so you're editing, not starting cold. You still copy, paste, and send yourself on every platform — Closetline organizes the decision, it doesn't take it away from you.
If you're managing this manually across several marketplaces right now, see what it looks like to stop.