"My two cents" and its longer version "put my two cents in" is an American idiomatic expression, taken from the original British idiom expression: to put in "my two pennies worth" or "my tuppence worth." It used to preface the tentative stating of one’s opinion. By deprecating the opinion to follow — suggesting its value is only two cents, a very small amount — the user of the phrase hopes to lessen the impact of a possibly contentious statement, showing politeness and humility. However, it is also sometimes used with irony when expressing a strongly felt opinion. The phrase is also used out of habit to preface uncontentious opinions.- taken from Wikipedia.