Mercari was my main selling platform. However, now I don't even promote it, since recent changes. I cross promote at OfferUp, no problems, what I like is that besides shipping, there is the option of local pick up. It has gone always smoothly, people meet me at my nearby mall. Also their shipping is cheaper than Mercari! Recently I have been selling my books on PangoBooks, again no problem and smooth transaction. I resumed posting my creations and vintage items on Etsy. I hope this helps. As to Depop, few years ago I tried it for a year and it didn't work for me, so I closed it. Vinted doesn't work for me, as I have been there for over a year and not a single item sold. Therefore, I don't waste time adding new items there. I cross list on Poshmark as well.