Would you be interested in Merchandise? (Patreon)

Bit of a strange question here...

I received an e-mail from Patreon saying they are now offering merchandise where I come up with the design and they handle all the shipping, fulfilment, support and everything else.

If I designed some things would there be any interest in buying them? They offer t-shirts, mugs, posters and that sort of thing.

I could try to think up some innocuous designs that could be worn in public or design stuff for home use only... I don't know, I only got the e-mail last night and I'm just interested if there is any demand from my lovely patrons.