While Mercari may be a legitimate online marketplace, it is unfortunately susceptible to scams. As noted, the scam often follows the same pattern: you purchase an item from a seller, and instead of using Mercari’s shipping system, the seller opts for a private shipment with tracking. This can lead to problems if the seller fails to send the item or if the item is counterfeit. As such, it is important to be cautious when shopping on Mercari.