Here’s what consumers have asked with answers from Poshmark staff and previous consumers.
After a week (not including Sunday's) of the seller not shipping an item you are given the option to cancel your order!
It all depends on the brand and uniqueness of your items. What I've found is that popular, higher-end brands (i. E PINK, Free People) sell quicker than less-known brands. Basic clothing with not much going on (like a plain blue knit sweater or shirt) are relatively hard to sell, because buyers can get the same item in a real life store for cheaper. If your sales are good in FB, you'll probably do well in Poshmark.
If you bought someone, and received the item and all is well, they want you to respond by clicking "I got it" or whatever so the money is released to the seller. They don't get paid immediately when you buy something. They only get paid once you respond via your account or email upon getting the item in the mail.