someone added one of my products to a collection found in their store

[WBartworks]

I didn't know this was even possible.  I am wondering why anyone would want to do that. Is that one of the ways to earn the 15% referral fee?

[CreativeLeahG]

Affiliates create collections with other Designers products to promote via their blogs and websites. They only make a referral when shared OFF the Zazzle platform.

[WBartworks]

So I am guessing it was put in their collection so that they could promote it along with all of their products in that given collection.  Is that common practice?

[Windy · Accepted solution]

I make a collection when I am getting ready to write a POD Postcard blog post. I take a few days to choose a few dozen cool postcards that I might want to put on my blog. Most of these are postcards from other designers. Then later, I go back to that collection and choose which postcards I want to feature on my POD Postcard blog. Then after that I just keep the collection, because I might want to refer to it and have an easy way to find the postcards I featured.

[WBartworks]

I think I understand now.  Thank you both, for explaining this to me!  I am certainly happy to have one of my products promoted!

[CreativeLeahG]

Many of my items have been added to other's collections so yes ... it would be a mix of whatever was needed to fit the niche they were promoting.