If you're working during Prime Day , you may be having some FOMO. Amazon's deals have been expanded to 48 hours this year, up from 36 last year, and 30 in 2017. We may celebrate prime day like it's a holiday, but do we really need everything in our carts? We spoke to, Kristen Berman Behavioral Scientist, Co-founder of Irrational Labs about the psychology behind the deals.