Marketing with postcards

[Lanique Carroll]

I have a few questions far as when it comes to post cards is there a difference when you send out yellow bright post cards vs a post card that is white or not brIGHT ? when sending out postcards to sellers numerous times to the same seller would it be a good idea to send a different designed post card ? Then the original one that you sent. Should the post card be professional or more so trying to get someone’s attention ?