Trusting users is a good way to stay connected with buyers/sellers that you've had good experiences with. Their offers will then be prioritized on the offer page. Blocking users is a good way to stay away from buyers/sellers you’ve had bad experiences with. If you’re selling cryptocurrency, your offers won’t be shown to them. If you’re buying cryptocurrency, you won’t be able to see their offers.
If you block a user, they won’t be able to contact you via Messenger.