Thumb Score: +10 Grubhub is offering New Grubhub+ Members through Amazon Prime: Spend $15+ on Grubhub and get $10 Off when you apply promo code PRIME10 at checkout. Thanks to Deal Editor Discombobulated for finding this deal. Note: Offer is not available for existing Grubhub+ members. Offer is valid only for new Grubhub+ members who sign up for Grubhub+ via their Amazon Prime account (free for Prime members).