A crackerjack box was the
disposable cardboard box used to hold popcorn or candy (sweets), though
over time has come to mean a similar box or container used to give away rather useless, cheap toys and/or giveaway items. So anything referred to as 'coming out of a crackerjack box' is being derided as useless, cheap or fake.
Did you get your degree out of a
Cracker jack box? (ie. your degree in
media studies / sociology etc. is worthless)
(From Meatloaf's "two out of three ain't bad"): There ain't no Coupe de Ville hiding at the bottom of a
Cracker jack box (you'll never find a valuable and exotic, vintage car in the bottom of a crackerjack box)