Shopping Ads

The shopping ad is the only place where you can serve and add back to somebody where they've already engaged with that specific product. There are actually multiple feeds inside the shopping campaign, so you can definitely break things out and try different things. So there's a lot of room for testing. Ean feed is basically so if you've seen on gogle, or you've probably been retargeted on facebook or gogle with an ad that shows five or six different pictures  with different products.