Amazon Prime Day's rising prominence as an anticipated shopping day is creating new opportunities for brands and sellers. Not only does it help boost sales during the mid-summer spending lull, but proactive marketing efforts can create a halo effect for brands that spurs ongoing results. Jeff Cohen, partner and CMO at ecommerce tool provider Seller Labs, spoke with eMarketer's Andrew Lipsman about what marketers should do before, during and after Prime Day to benefit from the shopping surge.