just once, when you buy an item it says how many uses it have. most items almost 99% of them are all one time use.

when you post a comment on someones human pets site, there is a little shopping cart logo with words that say "Add an item"

you can give items that you buy from peoples shops to other people. Usually people buy things for the pets they own.

Thank you for buying stuff at my shop~

How dare you buy yourself back from me! xDDD