Right as most of the forum members have priority of privacy and would not be willing to jump into this although you have good idea to sell some good merchandise for Bitcointalk lovers but you see they are physical items and needs to be delivered to some address and many will not be willing to hand out them.

If you see when there was community awards and prizes were to be handed out like holiday trip but the winners refused it to take because they didn't want to compromise their privacy with it and rewards were secondary for them even if the rewards were really good so paying for merchs will never be an option to them and compromise their security.

When there was Bitcointalk channel setup then there was suggestion of interviewing members in video but you see they refused it because they want to remain anonymous only and spend time over forum as usual only.

But you can give some samples to the viewers of how you will design products or merchs and see if you gain some customers from it and they have no problem with this business.