Why Do Events Collections Require a T-shirt?

[Scribbleprints]

I want to make a collection for a Thankgiving dinner event. I'm putting plates, invitations, tablecloths...all the things you would put on a thanksgiving table in it.   Why, to be an Event Collection does it need a t-shirt?

What if you were doing a wedding?  Do weddings really need t-shirts?

[Jadendreamer13]

Check out all the Thanksgiving T-Shirts on Zazzle. Folks search on them and buy them.

[Connie]

Each type of Event collection has different required products. T-shirts are not required in the wedding collections.

[KeegansCreation]

It is non-intuitive but rather based on their statistics for what sells for any given event. That's why it's different for every event. I didn't think people bought so many t shirts or mugs for Thanksgiving but according to Zazzle statistics they do. So I made them. This came up when this whole schema was introduced and people were baffled by the peculiar inclusion of certain products for certain collection types and a mod chimed in to explain that it was based on their sales statistics.