I recently made a purchase of an RTX 3070 Ultra graphics card which was cancelled on the 3rd day by the seller. The sellers have 3 days to ship or cancel the order. On the second day I messaged the seller with a polite and professional reminder to please give me an ETA on when the item would ship and so did the Mercari automated service. I did not receive a reply by the seller. I messaged the seller on the 3rd day with another polite friendly reminder to ship the item only to find that my order was cancelled without reason shortly after. I not only suffered a loss of this hard to get item for a good price but I lost out on another good opportunity having gone for Mercari instead. The sellers bear no financial penalty for not shipping an item and cancelling an order. If sellers had to forfeit say 20 to 30 percent of the sale they would be less likely to cancel an order to relist for a higher price or to sell to someone else that offered more and complete the sale outside of Mercari. This was my first experience and it left a bad taste in my mouth. I doubt that I will use Mercari again until they resolve the heavy cancellation issue. What I learned for the future is the following. Don't purchase from someone that has no reviews or history. If the order doesn't ship on the second day, you should probably cancel the order and move on. Avoid sellers that have many cancelled orders in their history. I have used Ebay many times and never had an order cancelled after I made the purchase. This is a bad practice by Mercari allowing sellers to shortchange their customers. It damages their name brand, reliability and new traffic customers like me. It also forces customer to vent their grievances about shady practices to the world. I was hoping for a good experience and an alternative to Ebay but got rejected instead. Even though Mercari does not allow sellers to drop ship and does not allow multiple accounts they do allow multiple accounts in the same household which only allows sellers to bypass the multiple accounts rule to be able to relist under another name with the same address. I'm very disappointed with the service and I hope this helps consumers out there to make a better choice where they spend their money and valuable time.