Participating Jamba Juice locations offer a Jamba Juice 16-oz. Smoothie for $1 during their Jamba Juice Dollar Days. That beats our January mention when we saw a 16-oz. smoothie for $2 and is among the best deals we've seen from Jamba Juice . It's valid from 9 am until 11 am every day from February 11 through 15. Click here for a list of participating locations.