Your cold traffic is whah drives your re-targeting. Especially when it comes to high AOV products because it will likely take the users few more visits to make that decision to buy. As a real life example, I’m moving house at the moment and I need to buy a new bed, sofa etc (£1000+ worth of purchases) and I’ve clicked a load of different ads but haven’t committed yet. But the ads I have been served ads that have helped me draw up a wish list. To the people who buy ads for this company, they probably think they’re ads are shit, but I haven’t bought it yet. If you cut your cold traffic, there’s a really really high chance you’ll cut off your retargeting performance as well. Combine your CPA’s across campaigns.