By all means let us know the shippers name, and if they do a good job for you. some business could go their way. They are not trying to vend their product without the vendors membership, and you are just relaying the hopefully positive experience you had with them. Nothing against the rules with that.
I would however wait until you have completed the transaction with them so as to make sure you are completely satisfied with the service and no "hidden" charges come up. Nothing like saying...hey guys, use this shipper they are good and cheap. Then having them turn the tables on you and having to come back on here and recant your endorsement of them.