It means you bought or traded something and unintentionally received more product(s) than what you paid or traded for. That additional product(s) was therefore “Free” however there was a transaction of money, goods, or services required to receive the free item therefore it was “on the cheap.”

Noun: a friend who is usually only called upon by a friend when a more primary/prominent friend is unavailable.

Taken from the term “second string” in an athletic competition situation. In football, if the star quarterback gets injured during a play, the second string is called off the bench to replace him/her. A “Second String Friend” is essentially benched until needed, if ever.

Synonyms: Plan B, Second Choice, Secondary Friend, Benched Until Needed