1
general::
1. To the utmost of one's power or ability, as in Coming onto the homestretch she ran for all she was worth. [Second half of 1800s] 2. for all or for what it's worth;for whatever it's worth. Even though it may not be important or valuable. For example, Here's my opinion, for what it's worth, or For whatever it's worth I've decided to take the train. [Late 1800s]
American Heritage Idioms