@Cat It’s as simple as including #zazzlemade on the end of your marketing blurb (eg - on your instagram caption/pinterest pin description/tweet whatever and just include the @zazzle too
Can’t say about whether it’s worth tagging Z on benable as I don’t use it. Zazzle would have to have an account on their to see the tag I guess.
It does work on pinterest as Zazzle has an account there